diff --git a/backend/build.gradle b/backend/build.gradle
index fa1c3665..3d01dc5c 100644
--- a/backend/build.gradle
+++ b/backend/build.gradle
@@ -95,6 +95,9 @@ dependencies {
 
 	// Thymleaf
 	implementation 'org.springframework.boot:spring-boot-starter-thymeleaf'
+
+    // Apache POI (Excel)
+    implementation 'org.apache.poi:poi-ooxml:5.5.1'
 }
 
 jacoco {
diff --git a/backend/src/main/java/org/sejongisc/backend/admin/controller/AdminUserController.java b/backend/src/main/java/org/sejongisc/backend/admin/controller/AdminUserController.java
index 2e733a27..a6a5ac15 100644
--- a/backend/src/main/java/org/sejongisc/backend/admin/controller/AdminUserController.java
+++ b/backend/src/main/java/org/sejongisc/backend/admin/controller/AdminUserController.java
@@ -4,10 +4,11 @@
 import io.swagger.v3.oas.annotations.tags.Tag;
 import lombok.RequiredArgsConstructor;
 import org.sejongisc.backend.admin.dto.AdminUserRequest;
-import org.sejongisc.backend.user.dto.UserInfoResponse; // 기존 DTO 활용
+import org.sejongisc.backend.admin.dto.AdminUserResponse;
+import org.sejongisc.backend.admin.dto.ExcelSyncResponse;
+import org.sejongisc.backend.admin.service.AdminUserService;
 import org.sejongisc.backend.user.entity.Role;
 import org.sejongisc.backend.user.entity.UserStatus;
-import org.sejongisc.backend.user.service.UserService;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.access.prepost.PreAuthorize;
@@ -15,7 +16,6 @@
 import org.springframework.web.multipart.MultipartFile;
 
 import java.util.List;
-import java.util.Map;
 import java.util.UUID;
 
 @RestController
@@ -24,55 +24,77 @@
 @Tag(name = "관리자 API", description = "운영진 및 개발자용 회원 관리 API")
 public class AdminUserController {
 
-    private final UserService userService;
+    private final AdminUserService adminUserService;
 
     // --- [회장/운영진용] 회원 관리 API ---
 
-    @Operation(summary = "엑셀 명단 업로드 및 동기화", description = "엑셀 파일을 업로드하여 신규 회원을 등록하고, 기존 회원의 기수/직위를 갱신합니다.")
+    @Operation(
+        summary = "엑셀 명단 업로드 및 동기화",
+        description = """
+        엑셀 파일을 업로드하여 신규 회원을 등록하고, 기존 회원의 기수/직위를 갱신합니다. (회장/관리자용)
+        - .xlsx 형식만 업로드 가능합니다. \s
+        - 학번 기준으로 회원을 생성하거나 기존 정보를 갱신합니다. \s
+        - 신규 회원의 초기 비밀번호는 전화번호 숫자만(예: 01012345678)으로 설정됩니다.
+        """
+    )
     @PostMapping(value = "/upload-excel", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
     @PreAuthorize("hasAnyRole('PRESIDENT', 'SYSTEM_ADMIN')") // 회장, 개발자만 가능
-    public ResponseEntity<?> uploadMemberExcel(@RequestPart("file") MultipartFile file) {
-        // 엑셀 파싱 및 DB 동기화 결과 반환
-        //ExcelSyncResultDto result = adminUserService.syncMembersFromExcel(file);
-        //return ResponseEntity.ok(result);
-        return null;
+    public ResponseEntity<ExcelSyncResponse> uploadMemberExcel(@RequestPart("file") MultipartFile file) {
+        return ResponseEntity.ok(adminUserService.syncUsersFromExcel(file));
     }
 
-    @Operation(summary = "전체 회원 목록 조회", description = "모든 회원의 정보를 조회합니다. (회장/관리자용)")
-    @GetMapping("")
-    @PreAuthorize("hasAnyRole('SYSTEM_ADMIN', 'MANAGER')")
-    public ResponseEntity<List<UserInfoResponse>> getAllUsers(@RequestBody AdminUserRequest request) {
-        //return ResponseEntity.ok(userService.findAllUsers());             // TODO : 전체 조회, 기수별 조회, 이름 검색 등 기능 추가 (페이징은 추후 고려)
-        return null;
+    @Operation(
+        summary = "전체 회원 목록 조회",
+        description = """
+        모든 회원의 정보를 조회합니다. (시스템 관리자용)
+        - 키워드, 기수, 권한(Role), 활동 상태(UserStatus) 조건으로 필터 조회합니다. \s
+        - 키워드는 이름, 학번, 이메일 기준으로 검색됩니다. \s
+        - 조건 미입력 시 전체 조회됩니다. \s
+        - 정렬 기준: 기수 최신순 → 이름 오름차순
+        """
+    )
+    @GetMapping
+    @PreAuthorize("hasAnyRole('SYSTEM_ADMIN')")
+    public ResponseEntity<List<AdminUserResponse>> getAllUsers(@ModelAttribute AdminUserRequest request) {
+        // TODO: 페이징 추후 고려
+        return ResponseEntity.ok(adminUserService.findAllUsers(request));
     }
 
-    @Operation(summary = "회원 활동 상태 변경", description = "ACTIVE, INACTIVE, GRADUATED 등으로 상태를 변경합니다.")
+    @Operation(summary = "회원 활동 상태 변경", description = "ACTIVE, INACTIVE, GRADUATED 등으로 상태를 변경합니다. (시스템 관리자용)")
     @PatchMapping("/{userId}/status")
-    @PreAuthorize("hasAnyRole('SYSTEM_ADMIN', 'MANAGER')")
+    @PreAuthorize("hasAnyRole('SYSTEM_ADMIN')")
     public ResponseEntity<?> updateUserStatus(
             @PathVariable UUID userId,
             @RequestParam UserStatus status) {
-        //userService.updateUserStatus(userId, status);
-        return ResponseEntity.ok(Map.of("message", "사용자 상태가 " + status + "(으)로 변경되었습니다."));
+        adminUserService.updateUserStatus(userId, status);
+        return ResponseEntity.noContent().build();
     }
 
     // --- [시스템 관리자용 or 회장용] 권한 및 계정 제어 API ---
     // TODO : 회장 권한 논의 필요
-    @Operation(summary = "회원 권한 변경", description = "특정 유저의 Role(PRESIDENT, VICE_PRESIDENT, TEAM_LEADER)을 변경합니다.)")
+    @Operation(summary = "회원 권한 변경", description = "특정 유저의 Role(PRESIDENT, VICE_PRESIDENT, TEAM_LEADER)을 변경합니다. (시스템 관리자용)")
     @PatchMapping("/{userId}/role")
     @PreAuthorize("hasRole('SYSTEM_ADMIN')")
     public ResponseEntity<?> updateUserRole(
             @PathVariable UUID userId,
             @RequestParam Role role) {
-        //userService.updateUserRole(userId, role);
-        return ResponseEntity.ok(Map.of("message", "사용자 권한이 " + role + "(으)로 변경되었습니다."));
+        adminUserService.updateUserRole(userId, role);
+        return ResponseEntity.noContent().build();
     }
 
-    @Operation(summary = "회원 강제 탈퇴", description = "시스템에서 유저를 완전히 삭제합니다. (시스템 관리자용)")
+    @Operation(summary = "선배(SENIOR) 등급 변경", description = "특정 유저를 선배(SENIOR) 등급으로 변경합니다. (회장/관리자용)")
+    @PatchMapping("/{userId}/senior")
+    @PreAuthorize("hasAnyRole('PRESIDENT', 'SYSTEM_ADMIN')")
+    public ResponseEntity<Void> promoteToSenior(@PathVariable UUID userId) {
+        adminUserService.promoteToSenior(userId);
+        return ResponseEntity.noContent().build();
+    }
+
+    @Operation(summary = "회원 강제 탈퇴", description = "시스템에서 유저를 탈퇴 처리합니다. (시스템 관리자용)")
     @DeleteMapping("/{userId}")
     @PreAuthorize("hasRole('SYSTEM_ADMIN')")
     public ResponseEntity<?> forceDeleteUser(@PathVariable UUID userId) {
-        //userService.deleteUserWithOauth(userId);
-        return ResponseEntity.ok(Map.of("message", "해당 사용자가 시스템에서 완전히 삭제되었습니다."));
+        adminUserService.deleteUser(userId);
+        return ResponseEntity.noContent().build();
     }
 }
\ No newline at end of file
diff --git a/backend/src/main/java/org/sejongisc/backend/admin/dto/AdminUserRequest.java b/backend/src/main/java/org/sejongisc/backend/admin/dto/AdminUserRequest.java
index a393dc81..891242d8 100644
--- a/backend/src/main/java/org/sejongisc/backend/admin/dto/AdminUserRequest.java
+++ b/backend/src/main/java/org/sejongisc/backend/admin/dto/AdminUserRequest.java
@@ -1,5 +1,15 @@
 package org.sejongisc.backend.admin.dto;
 
-public class AdminUserRequest {
+import org.sejongisc.backend.user.entity.Role;
+import org.sejongisc.backend.user.entity.UserStatus;
 
-}
+/**
+ * 관리자 페이지의 사용자 필터링/검색 조회 요청
+ */
+public record AdminUserRequest (
+    String keyword, // 키워드
+    Integer generation, // 기수
+    Role role, // 권한
+    UserStatus status // 상태
+) {
+}
\ No newline at end of file
diff --git a/backend/src/main/java/org/sejongisc/backend/admin/dto/AdminUserResponse.java b/backend/src/main/java/org/sejongisc/backend/admin/dto/AdminUserResponse.java
new file mode 100644
index 00000000..90f5dd8f
--- /dev/null
+++ b/backend/src/main/java/org/sejongisc/backend/admin/dto/AdminUserResponse.java
@@ -0,0 +1,25 @@
+package org.sejongisc.backend.admin.dto;
+
+import lombok.Builder;
+import org.sejongisc.backend.user.entity.*;
+
+import java.util.UUID;
+
+@Builder
+public record AdminUserResponse(
+    UUID id,
+    String studentId,
+    String name,
+    String email,
+    String phoneNumber,
+    long point, // Account 엔티티의 balance 값
+    Grade grade,
+    Role role,
+    UserStatus status,
+    Integer generation,
+    String college,
+    String department,
+    String teamName,
+    String positionName
+) {
+}
\ No newline at end of file
diff --git a/backend/src/main/java/org/sejongisc/backend/admin/dto/ExcelSyncResponse.java b/backend/src/main/java/org/sejongisc/backend/admin/dto/ExcelSyncResponse.java
new file mode 100644
index 00000000..9cab7474
--- /dev/null
+++ b/backend/src/main/java/org/sejongisc/backend/admin/dto/ExcelSyncResponse.java
@@ -0,0 +1,10 @@
+package org.sejongisc.backend.admin.dto;
+
+/**
+ * 엑셀 동기화 결과 응답
+ */
+public record ExcelSyncResponse(
+    int createdCount,
+    int updatedCount
+) {
+}
\ No newline at end of file
diff --git a/backend/src/main/java/org/sejongisc/backend/admin/dto/UserExcelRow.java b/backend/src/main/java/org/sejongisc/backend/admin/dto/UserExcelRow.java
new file mode 100644
index 00000000..e86c6701
--- /dev/null
+++ b/backend/src/main/java/org/sejongisc/backend/admin/dto/UserExcelRow.java
@@ -0,0 +1,21 @@
+package org.sejongisc.backend.admin.dto;
+
+import lombok.Builder;
+
+/**
+ * 엑셀 파일의 한 행 데이터를 담는 Row
+ */
+@Builder
+public record UserExcelRow(
+    String studentId,
+    String name,
+    String phone,
+    String teamName,
+    String generation,
+    String college,
+    String department,
+    String grade,
+    String position,
+    String gender
+) {
+}
diff --git a/backend/src/main/java/org/sejongisc/backend/admin/repository/AdminUserRepository.java b/backend/src/main/java/org/sejongisc/backend/admin/repository/AdminUserRepository.java
new file mode 100644
index 00000000..0b848c87
--- /dev/null
+++ b/backend/src/main/java/org/sejongisc/backend/admin/repository/AdminUserRepository.java
@@ -0,0 +1,65 @@
+package org.sejongisc.backend.admin.repository;
+
+import org.sejongisc.backend.admin.dto.AdminUserResponse;
+import org.sejongisc.backend.point.entity.AccountType;
+import org.sejongisc.backend.user.entity.Role;
+import org.sejongisc.backend.user.entity.User;
+import org.sejongisc.backend.user.entity.UserStatus;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.util.List;
+import java.util.UUID;
+
+/**
+ * 관리자 화면용 User 조회 전용 레포지토리
+ * - User 도메인의 기본 CRUD는 user 패키지의 UserRepository에서 담당
+ * - 해당 클래스는 Admin 페이지에서만 사용되는 조회 쿼리와 Admin DTO로의 프로젝션 로직을 정의
+ */
+public interface AdminUserRepository extends JpaRepository<User, UUID> {
+
+    @Query("""
+        SELECT new org.sejongisc.backend.admin.dto.AdminUserResponse(
+            u.userId,
+            u.studentId,
+            u.name,
+            u.email,
+            u.phoneNumber,
+            COALESCE(a.balance, 0),
+            u.grade,
+            u.role,
+            u.status,
+            u.generation,
+            u.college,
+            u.department,
+            u.teamName,
+            u.positionName
+        )
+        FROM User u
+        LEFT JOIN Account a
+            ON u.userId = a.ownerId
+            AND a.type = :accountType
+        WHERE
+            (:keyword IS NULL OR
+                u.name LIKE %:keyword% OR
+                u.email LIKE %:keyword% OR
+                (:numericKeyword IS NOT NULL AND (
+                    u.studentId LIKE %:numericKeyword% OR
+                    u.phoneNumber LIKE %:numericKeyword%
+                ))
+            )
+            AND (:generation IS NULL OR u.generation = :generation)
+            AND (:role IS NULL OR u.role = :role)
+            AND (:status IS NULL OR u.status = :status)
+        ORDER BY u.generation DESC, u.name ASC
+        """)
+    List<AdminUserResponse> findAllByAdminFilter(
+        @Param("keyword") String keyword,
+        @Param("numericKeyword") String numericKeyword,
+        @Param("generation") Integer generation,
+        @Param("role") Role role,
+        @Param("status") UserStatus status,
+        @Param("accountType") AccountType accountType
+    );
+}
\ No newline at end of file
diff --git a/backend/src/main/java/org/sejongisc/backend/admin/service/AdminUserService.java b/backend/src/main/java/org/sejongisc/backend/admin/service/AdminUserService.java
new file mode 100644
index 00000000..e52ce615
--- /dev/null
+++ b/backend/src/main/java/org/sejongisc/backend/admin/service/AdminUserService.java
@@ -0,0 +1,171 @@
+package org.sejongisc.backend.admin.service;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.poi.ss.usermodel.*;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+import org.sejongisc.backend.admin.dto.AdminUserRequest;
+import org.sejongisc.backend.admin.dto.AdminUserResponse;
+import org.sejongisc.backend.admin.dto.ExcelSyncResponse;
+import org.sejongisc.backend.admin.dto.UserExcelRow;
+import org.sejongisc.backend.admin.repository.AdminUserRepository;
+import org.sejongisc.backend.common.exception.CustomException;
+import org.sejongisc.backend.common.exception.ErrorCode;
+import org.sejongisc.backend.point.entity.AccountType;
+import org.sejongisc.backend.user.entity.*;
+import org.sejongisc.backend.user.service.UserService;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.web.multipart.MultipartFile;
+
+import java.io.InputStream;
+import java.util.*;
+
+@Slf4j
+@Service
+@RequiredArgsConstructor
+public class AdminUserService {
+    private final AdminUserRepository adminUserRepository;
+    private final AdminUserSyncService adminUserSyncService;
+    private final UserService userService;
+
+    /**
+     * 엑셀 파일을 읽어 동기화 프로세스 시작
+     */
+    public ExcelSyncResponse syncUsersFromExcel(MultipartFile file) {
+        DataFormatter formatter = new DataFormatter();
+
+        // 엑셀 파일 검증
+        validateFile(file);
+        List<UserExcelRow> excelRows = new ArrayList<>();
+
+        try (InputStream is = file.getInputStream(); Workbook workbook = new XSSFWorkbook(is)) {
+            Sheet sheet = workbook.getSheetAt(0);
+
+            for (int i = 1; i <= sheet.getLastRowNum(); i++) {
+                Row row = sheet.getRow(i);
+                if (row == null) continue;
+
+                // 학번 없으면 빈 행으로 간주
+                String studentId = getCellValue(row, 4, formatter);
+                if (studentId.isEmpty()) continue;
+
+                // 필수값 검증 및 UserExcelRow 리스트에 추가
+                excelRows.add(buildExcelRow(row, studentId, i, formatter));
+            }
+
+            // 추가할 내용이 없는 빈 파일의 경우 예외
+            if (excelRows.isEmpty()) {
+                throw new CustomException(ErrorCode.EMPTY_FILE);
+            }
+            log.info("엑셀 파일 파싱 완료: 파일명={}, 총 건수={}", file.getOriginalFilename(), excelRows.size());
+        } catch (CustomException e) {
+            throw e;
+        } catch (Exception e) {
+            log.error("엑셀 동기화 중 오류 발생: ", e);
+            throw new CustomException(ErrorCode.INTERNAL_SERVER_ERROR);
+        }
+
+        return adminUserSyncService.syncMemberData(excelRows);
+    }
+
+    /**
+     * 관리자 필터 조건(키워드, 기수, 권한, 상태)에 따른 사용자 목록 조회
+     */
+    @Transactional(readOnly = true)
+    public List<AdminUserResponse> findAllUsers(AdminUserRequest request) {
+        String keyword = request.keyword();
+        String numericKeyword = null;
+        if (keyword != null && !keyword.isEmpty()) {
+            // 학번 및 전화번호 검색을 위해 숫자만 남긴 키워드
+            numericKeyword = keyword.replaceAll("[^0-9]", "");
+            if (numericKeyword.isEmpty()) numericKeyword = null;
+        }
+
+        return adminUserRepository.findAllByAdminFilter(
+            keyword, numericKeyword, request.generation(), request.role(), request.status(), AccountType.USER
+        );
+    }
+
+    /**
+     * 특정 사용자의 활동 상태 변경
+     */
+    @Transactional
+    public void updateUserStatus(UUID userId, UserStatus status) {
+        userService.updateUserStatus(userId, status);
+    }
+
+    /**
+     * 특정 사용자의 시스템 권한(Role) 변경
+     */
+    @Transactional
+    public void updateUserRole(UUID userId, Role role) {
+        userService.updateUserRole(userId, role);
+    }
+
+    /**
+     * 특정 사용자를 선배(SENIOR) 등급으로 변경
+     */
+    @Transactional
+    public void promoteToSenior(UUID userId) {
+        userService.promoteToSenior(userId);
+    }
+
+    /**
+     * 사용자 계정 삭제 (soft delete)
+     */
+    @Transactional
+    public void deleteUser(UUID userId) {
+        userService.deleteUserSoftDelete(userId);
+        log.info("관리자에 의한 강제 탈퇴 완료: userId={}", userId);
+    }
+
+    /**
+     * 엑셀 파일의 셀을 문자열로 변환
+     */
+    private String getCellValue(Row row, int cellIndex, DataFormatter formatter) {
+        Cell cell = row.getCell(cellIndex);
+        if (cell == null) return "";
+
+        return formatter.formatCellValue(cell).trim();
+    }
+
+    /**
+     * 엑셀 파일 검증
+     */
+    private void validateFile(MultipartFile file) {
+        if (file == null || file.isEmpty()) throw new CustomException(ErrorCode.EMPTY_FILE);
+
+        String fileName = file.getOriginalFilename();
+        if (fileName == null || !fileName.toLowerCase(Locale.ROOT).endsWith(".xlsx")) throw new CustomException(ErrorCode.INVALID_FILE_FORMAT);
+    }
+
+    /**
+     * 엑셀의 특정 행을 읽어 UserExcelRow 생성
+     */
+    private UserExcelRow buildExcelRow(Row row, String studentId, int rowIndex, DataFormatter formatter) {
+        String name = getCellValue(row, 3, formatter);
+        String phone = getCellValue(row, 5, formatter);
+        String team = getCellValue(row, 1, formatter);
+        String grade = getCellValue(row, 8, formatter);
+
+        // 학번은 있지만 필수 데이터가 누락된 경우
+        if (name.isEmpty() || phone.isEmpty() || team.isEmpty() || grade.isEmpty()) {
+            log.error("엑셀 데이터 누락: 행 번호={}, 학번={}", rowIndex + 1, studentId);
+            throw new CustomException(ErrorCode.INVALID_EXCEL_STRUCTURE);
+        }
+
+        return UserExcelRow.builder()
+            .studentId(studentId)
+            .name(name)
+            .phone(phone.replaceAll("[^0-9]", ""))
+            .teamName(team)
+            .generation(getCellValue(row, 2, formatter))
+            .college(getCellValue(row, 6, formatter))
+            .department(getCellValue(row, 7, formatter))
+            .grade(grade)
+            .position(getCellValue(row, 9, formatter))
+            .gender(getCellValue(row, 10, formatter))
+            .build();
+    }
+}
\ No newline at end of file
diff --git a/backend/src/main/java/org/sejongisc/backend/admin/service/AdminUserSyncService.java b/backend/src/main/java/org/sejongisc/backend/admin/service/AdminUserSyncService.java
new file mode 100644
index 00000000..a3e1fd8c
--- /dev/null
+++ b/backend/src/main/java/org/sejongisc/backend/admin/service/AdminUserSyncService.java
@@ -0,0 +1,111 @@
+package org.sejongisc.backend.admin.service;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.sejongisc.backend.admin.dto.ExcelSyncResponse;
+import org.sejongisc.backend.admin.dto.UserExcelRow;
+import org.sejongisc.backend.common.annotation.OptimisticRetry;
+import org.sejongisc.backend.point.dto.AccountEntry;
+import org.sejongisc.backend.point.entity.Account;
+import org.sejongisc.backend.point.entity.AccountName;
+import org.sejongisc.backend.point.entity.TransactionReason;
+import org.sejongisc.backend.point.service.AccountService;
+import org.sejongisc.backend.point.service.PointLedgerService;
+import org.sejongisc.backend.user.entity.*;
+import org.sejongisc.backend.user.repository.UserRepository;
+import org.springframework.security.crypto.password.PasswordEncoder;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+import java.util.Optional;
+
+@Slf4j
+@Service
+@RequiredArgsConstructor
+public class AdminUserSyncService {
+    private final UserRepository userRepository;
+    private final PasswordEncoder passwordEncoder;
+    private final AccountService accountService;
+    private final PointLedgerService pointLedgerService;
+
+    /**
+     * 엑셀로부터 추출된 사용자 데이터를 DB와 동기화
+     */
+    @Transactional
+    @OptimisticRetry
+    public ExcelSyncResponse syncMemberData(List<UserExcelRow> excelRows) {
+        int createdCount = 0;
+        int updatedCount = 0;
+
+        // 기존 활동 인원 일괄 비활성화 (SYSTEM_ADMIN 제외)
+        userRepository.findAllByStatus(UserStatus.ACTIVE)
+            .stream()
+            .filter(user -> user.getRole() != Role.SYSTEM_ADMIN)
+            .forEach(user -> user.setStatus(UserStatus.INACTIVE));
+
+        for (UserExcelRow rowData : excelRows) {
+            Optional<User> existingUser = userRepository.findByStudentId(rowData.studentId());
+            boolean isNew = existingUser.isEmpty();
+
+            // 기존 사용자 조회, 없으면 신규 사용자 생성
+            User user = existingUser.orElseGet(() -> User.builder()
+                .studentId(rowData.studentId())
+                .passwordHash(passwordEncoder.encode(rowData.phone()))
+                .build());
+
+            // 엑셀 데이터 매핑 및 ACTIVE 상태 복구
+            updateUserFromRow(user, rowData);
+            User savedUser = userRepository.save(user);
+
+            if (isNew) {
+                createdCount++;
+                // 계정 생성 및 가입 보상 포인트 지급
+                Account userAccount = accountService.createUserAccount(savedUser.getUserId());
+                pointLedgerService.processTransaction(
+                    TransactionReason.SIGNUP_REWARD,
+                    savedUser.getUserId(),
+                    AccountEntry.credit(accountService.getAccountByName(AccountName.SYSTEM_ISSUANCE), 100L),
+                    AccountEntry.debit(userAccount, 100L)
+                );
+                log.info("신규 사용자 자동 가입 및 포인트 지급 완료: {}", user.getStudentId());
+            } else {
+                updatedCount++;
+            }
+        }
+
+        log.info("엑셀 사용자 데이터 동기화 완료: 신규 등록={}, 갱신={}", createdCount, updatedCount);
+        return new ExcelSyncResponse(createdCount, updatedCount);
+    }
+
+    /**
+     * 엑셀 행 데이터를 유저 엔티티 필드에 매핑
+     */
+    private void updateUserFromRow(User user, UserExcelRow rowData) {
+        Integer generation = parseGeneration(rowData.generation());
+        Grade grade = Grade.fromString(rowData.grade());
+        Role role = Role.fromPosition(rowData.position());
+        Gender gender = Gender.fromString(rowData.gender());
+
+        user.applyExcelData(
+            rowData.name(),
+            rowData.phone(),
+            rowData.teamName(),
+            generation,
+            rowData.college(),
+            rowData.department(),
+            grade,
+            rowData.position(),
+            role,
+            gender
+        );
+    }
+
+    /**
+     * 기수 문자열에서 숫자만 추출하여 파싱
+     */
+    private int parseGeneration(String genStr) {
+        String clean = genStr.replaceAll("[^0-9]", "");
+        return clean.isEmpty() ? 0 : Integer.parseInt(clean);
+    }
+}
\ No newline at end of file
diff --git a/backend/src/main/java/org/sejongisc/backend/common/auth/service/AuthService.java b/backend/src/main/java/org/sejongisc/backend/common/auth/service/AuthService.java
index 3950c2ad..a09f7e0c 100644
--- a/backend/src/main/java/org/sejongisc/backend/common/auth/service/AuthService.java
+++ b/backend/src/main/java/org/sejongisc/backend/common/auth/service/AuthService.java
@@ -13,7 +13,6 @@
 import org.sejongisc.backend.common.auth.dto.AuthRequest;
 import org.sejongisc.backend.common.auth.dto.AuthResponse;
 import org.sejongisc.backend.user.entity.User;
-import org.sejongisc.backend.user.util.PasswordPolicyValidator;
 import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.stereotype.Service;
 
@@ -34,10 +33,18 @@ public class AuthService {
     public AuthResponse login(AuthRequest request) {
         User user = userRepository.findByStudentId(request.getStudentId())
                 .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-        String trimmedPassword = PasswordPolicyValidator.getValidatedPassword(request.getPassword());
-        if (user.getPasswordHash() == null || !passwordEncoder.matches(trimmedPassword, user.getPasswordHash())) {
+
+        // 탈퇴 회원 로그인 차단
+        if (!user.canLogin()) {
+            throw new CustomException(ErrorCode.USER_WITHDRAWN);
+        }
+
+        // 비밀번호 일치 확인
+        if (user.getPasswordHash() == null ||
+            !passwordEncoder.matches(request.getPassword().trim(), user.getPasswordHash())) {
             throw new CustomException(ErrorCode.UNAUTHORIZED);
         }
+
         String accessToken = jwtProvider.createToken(user.getUserId(), user.getRole(), user.getEmail());
         String refreshToken = jwtProvider.createRefreshToken(user.getUserId());
 
diff --git a/backend/src/main/java/org/sejongisc/backend/common/exception/ErrorCode.java b/backend/src/main/java/org/sejongisc/backend/common/exception/ErrorCode.java
index fc668015..6dab44dd 100644
--- a/backend/src/main/java/org/sejongisc/backend/common/exception/ErrorCode.java
+++ b/backend/src/main/java/org/sejongisc/backend/common/exception/ErrorCode.java
@@ -89,6 +89,13 @@ public enum ErrorCode {
   DUPLICATE_PHONE(HttpStatus.CONFLICT, "이미 사용 중인 전화번호입니다."),
   DUPLICATE_USER(HttpStatus.CONFLICT, "이미 가입된 사용자입니다."),
   INVALID_INPUT(HttpStatus.BAD_REQUEST, "입력값이 올바르지 않습니다."),
+  USER_WITHDRAWN(HttpStatus.FORBIDDEN, "탈퇴한 회원은 로그인할 수 없습니다."),
+
+  // EXCEL
+
+  INVALID_FILE_FORMAT(HttpStatus.BAD_REQUEST, "지원하지 않는 파일 형식입니다. .xlsx 파일을 업로드해주세요."),
+  INVALID_EXCEL_STRUCTURE(HttpStatus.UNPROCESSABLE_ENTITY, "엑셀 양식이 일치하지 않습니다. 필수 컬럼을 확인해주세요."),
+  EMPTY_FILE(HttpStatus.BAD_REQUEST, "업로드된 파일이 비어있습니다."),
 
   // BETTING
 
diff --git a/backend/src/main/java/org/sejongisc/backend/point/entity/Account.java b/backend/src/main/java/org/sejongisc/backend/point/entity/Account.java
index 5cd43703..f33e92b7 100644
--- a/backend/src/main/java/org/sejongisc/backend/point/entity/Account.java
+++ b/backend/src/main/java/org/sejongisc/backend/point/entity/Account.java
@@ -16,6 +16,12 @@
 @NoArgsConstructor
 @AllArgsConstructor
 @Builder
+@Table(
+    name = "account",
+    uniqueConstraints = {
+        @UniqueConstraint(name = "uk_account_owner_type", columnNames = {"owner_id", "type"})
+    }
+)
 public class Account extends BasePostgresEntity {
   @Id
   @GeneratedValue(strategy = GenerationType.UUID)
diff --git a/backend/src/main/java/org/sejongisc/backend/user/entity/Gender.java b/backend/src/main/java/org/sejongisc/backend/user/entity/Gender.java
index 5c1da2ee..50bf80e8 100644
--- a/backend/src/main/java/org/sejongisc/backend/user/entity/Gender.java
+++ b/backend/src/main/java/org/sejongisc/backend/user/entity/Gender.java
@@ -2,5 +2,16 @@
 
 public enum Gender {
   MALE,
-  FEMALE
+  FEMALE;
+
+  public static Gender fromString(String genderStr) {
+    if (genderStr == null || genderStr.isBlank()) {
+      return null;
+    }
+
+    if (genderStr.contains("남")) return MALE;
+    if (genderStr.contains("여")) return FEMALE;
+
+    return null;
+  }
 }
diff --git a/backend/src/main/java/org/sejongisc/backend/user/entity/Grade.java b/backend/src/main/java/org/sejongisc/backend/user/entity/Grade.java
new file mode 100644
index 00000000..d405b49b
--- /dev/null
+++ b/backend/src/main/java/org/sejongisc/backend/user/entity/Grade.java
@@ -0,0 +1,18 @@
+package org.sejongisc.backend.user.entity;
+
+public enum Grade {
+  NEW_MEMBER, // 신입부원
+  ASSOCIATE_MEMBER, // 준회원
+  REGULAR_MEMBER, // 정회원
+  SENIOR; // 선배/OB
+
+  public static Grade fromString(String gradeStr) {
+    if (gradeStr == null) return NEW_MEMBER;
+
+    if (gradeStr.contains("정회원")) return REGULAR_MEMBER;
+    if (gradeStr.contains("준회원")) return ASSOCIATE_MEMBER;
+    if (gradeStr.contains("선배") || gradeStr.contains("OB")) return SENIOR;
+
+    return NEW_MEMBER;
+  }
+}
diff --git a/backend/src/main/java/org/sejongisc/backend/user/entity/Role.java b/backend/src/main/java/org/sejongisc/backend/user/entity/Role.java
index 590b5a20..7aad5982 100644
--- a/backend/src/main/java/org/sejongisc/backend/user/entity/Role.java
+++ b/backend/src/main/java/org/sejongisc/backend/user/entity/Role.java
@@ -3,11 +3,31 @@
 // 일반 회원가입 : 회장 승인이 있어야만 설정 가능
 // 엑셀 회원가입 : 회장 승인 없이 설정 가능 (user.isManagerPosition 으로 판단)
 public enum Role {
-    SYSTEM_ADMIN,      // 시스템 관리자
-    PRESIDENT,          // 회장
-    VICE_PRESIDENT,     // 부회장
-    TEAM_LEADER,        // 팀장
-    TEAM_MEMBER,        // 부원
-    PENDING_MEMBER;     // 대기회원 (회장이 승인 전 상태)
-    // 추가 가능 : SENIOR (선배/OB): 게시물 열람 위주 (포인트 활동 등은 제한 가능)
+  SYSTEM_ADMIN,      // 시스템 관리자
+  PRESIDENT,          // 회장
+  VICE_PRESIDENT,     // 부회장
+  TEAM_LEADER,        // 팀장
+  TEAM_MEMBER,        // 부원
+  PENDING_MEMBER;     // 대기회원 (회장이 승인 전 상태)
+  // 추가 가능 : SENIOR (선배/OB): 게시물 열람 위주 (포인트 활동 등은 제한 가능)
+
+  public static Role fromPosition(String position) {
+    if (position == null || position.isBlank()) {
+      return TEAM_MEMBER;
+    }
+
+    if (position.contains("회장") && !position.contains("부회장")) {
+      return PRESIDENT;
+    }
+
+    if (position.contains("부회장") || position.contains("부대표자")) {
+      return VICE_PRESIDENT;
+    }
+
+    if (position.contains("팀장")) {
+      return TEAM_LEADER;
+    }
+
+    return TEAM_MEMBER;
+  }
 }
\ No newline at end of file
diff --git a/backend/src/main/java/org/sejongisc/backend/user/entity/User.java b/backend/src/main/java/org/sejongisc/backend/user/entity/User.java
index 3f1feb00..ff1ba46d 100644
--- a/backend/src/main/java/org/sejongisc/backend/user/entity/User.java
+++ b/backend/src/main/java/org/sejongisc/backend/user/entity/User.java
@@ -49,8 +49,10 @@ public class User extends BasePostgresEntity{
     @Enumerated(EnumType.STRING)
     private Gender gender;       // 성별
 
-    @Column(name = "is_new_member", nullable = false)
-    private boolean isNewMember; // 신규 여부 (포인트나 이벤트 대상자 선정용)
+    @Enumerated(EnumType.STRING)
+    @Column(nullable = false)
+    @Builder.Default
+    private Grade grade = Grade.NEW_MEMBER; // 신입/준/정회원
 
     @Enumerated(EnumType.STRING)
     @Column(nullable = false)
@@ -100,13 +102,16 @@ public void prePersist() {
             this.point = 0;
         }
     }
-    public void updatePoint(int amount) {
-        this.point += amount;
+
+    // 로그인 가능 여부
+    public boolean canLogin() {
+        return this.status != UserStatus.OUT;
     }
 
+
     public static User createUserWithSignupAndPending(SignupRequest request, String encodedPw) {
         return User.builder()
-            .role(Role.TEAM_MEMBER)     // TODO : 운영진 승인 로직 추가 후 PENDING_MEMBER로 변경 필요
+            .role(Role.PENDING_MEMBER)
             .studentId(request.getStudentId())
             .name(request.getName())
             .passwordHash(encodedPw)
@@ -117,9 +122,35 @@ public static User createUserWithSignupAndPending(SignupRequest request, String
             .department(request.getDepartment())    // 학과
             .generation(request.getGeneration())    //
             .teamName(request.getTeamName())        // 소속 팀명
-            .isNewMember(true)                      // 신규 가입자
+            .grade(Grade.NEW_MEMBER)                // 신규 가입자
             .point(0)
             .status(UserStatus.ACTIVE)              // 기본 활동 상태
             .build();
     }
+
+    public void applyExcelData(
+        String name,
+        String phone,
+        String teamName,
+        Integer generation,
+        String college,
+        String department,
+        Grade grade,
+        String position,
+        Role role,
+        Gender gender
+    ) {
+        this.name = name;
+        this.phoneNumber = phone;
+        this.teamName = teamName;
+        this.generation = generation;
+        this.college = college;
+        this.department = department;
+        this.status = UserStatus.ACTIVE;
+        this.grade = grade;
+        this.positionName = position;
+        this.role = role;
+        this.gender = gender;
+    }
+
 }
diff --git a/backend/src/main/java/org/sejongisc/backend/user/entity/UserStatus.java b/backend/src/main/java/org/sejongisc/backend/user/entity/UserStatus.java
index 65a8d51c..4882ea16 100644
--- a/backend/src/main/java/org/sejongisc/backend/user/entity/UserStatus.java
+++ b/backend/src/main/java/org/sejongisc/backend/user/entity/UserStatus.java
@@ -10,8 +10,7 @@ public enum UserStatus {
   ACTIVE("활동 중"),
   INACTIVE("활동 중지"),
   GRADUATED("졸업생"),
-  OUT("탈퇴"),
-  PENDING("승인 대기");
+  OUT("탈퇴");
 
   private final String description; // 한글 명칭
 }
diff --git a/backend/src/main/java/org/sejongisc/backend/user/repository/UserRepository.java b/backend/src/main/java/org/sejongisc/backend/user/repository/UserRepository.java
index 56e366a6..0966f14b 100644
--- a/backend/src/main/java/org/sejongisc/backend/user/repository/UserRepository.java
+++ b/backend/src/main/java/org/sejongisc/backend/user/repository/UserRepository.java
@@ -2,6 +2,7 @@
 
 
 import org.sejongisc.backend.user.entity.User;
+import org.sejongisc.backend.user.entity.UserStatus;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
 
@@ -20,8 +21,11 @@ public interface UserRepository extends JpaRepository<User, UUID> {
     @Query(
         "SELECT u FROM User u " +
         "LEFT JOIN Account a ON u.userId = a.ownerId " +
-        "WHERE a.accountId IS NULL")
+        "WHERE a.accountId IS NULL"
+    )
     List<User> findAllUsersMissingAccount();
 
     Optional<User> findByStudentId(String studentId);
+
+    List<User> findAllByStatus(UserStatus status);
 }
diff --git a/backend/src/main/java/org/sejongisc/backend/user/service/UserService.java b/backend/src/main/java/org/sejongisc/backend/user/service/UserService.java
index dcdeaf3e..a6ff3827 100644
--- a/backend/src/main/java/org/sejongisc/backend/user/service/UserService.java
+++ b/backend/src/main/java/org/sejongisc/backend/user/service/UserService.java
@@ -18,6 +18,8 @@
 import org.sejongisc.backend.point.service.AccountService;
 import org.sejongisc.backend.point.service.PointLedgerService;
 import org.sejongisc.backend.user.dto.UserUpdateRequest;
+import org.sejongisc.backend.user.entity.Grade;
+import org.sejongisc.backend.user.entity.Role;
 import org.sejongisc.backend.user.entity.User;
 import org.sejongisc.backend.user.entity.UserStatus;
 import org.sejongisc.backend.user.repository.UserRepository;
@@ -140,12 +142,43 @@ public void resetPasswordByToken(String resetToken, String newPassword) {
         refreshTokenService.deleteByUserId(user.getUserId());
     }
 
+    @Transactional(readOnly = true)
     public List<User> findAllUsersMissingAccount() {
         return userRepository.findAllUsersMissingAccount();
     }
 
+    @Transactional
+    public void updateUserStatus(UUID userId, UserStatus status) {
+        User user = findUser(userId);
+        user.setStatus(status);
+        log.info("사용자 상태 변경 완료: userId={}", userId);
+    }
+
+    @Transactional
+    public void updateUserRole(UUID userId, Role role) {
+        User user = findUser(userId);
+        user.setRole(role);
+        log.info("사용자 권한 변경 완료: userId={}", userId);
+    }
+
+    @Transactional
+    public void promoteToSenior(UUID userId) {
+        User user = findUser(userId);
+
+        // grade 및 status 변경
+        user.setGrade(Grade.SENIOR);
+        user.setStatus(UserStatus.GRADUATED);
+
+        log.info("선배 등급 전환 완료: userId={}, 학번={}", userId, user.getStudentId());
+    }
+
     // --- 내부 헬퍼 메서드 ---
 
+    private User findUser(UUID userId) {
+        return userRepository.findById(userId)
+            .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
+    }
+
     private String validateNotBlank(String value, String fieldName) {
         if (value == null || value.trim().isEmpty()) {
             throw new CustomException(ErrorCode.INVALID_INPUT);