diff --git a/.chronus/changes/enum_mix_type-2024-4-21-20-58-13.md b/.chronus/changes/enum_mix_type-2024-4-21-20-58-13.md
new file mode 100644
index 0000000000..bded09ca6a
--- /dev/null
+++ b/.chronus/changes/enum_mix_type-2024-4-21-20-58-13.md
@@ -0,0 +1,7 @@
+---
+changeKind: breaking
+packages:
+  - "@azure-tools/typespec-client-generator-core"
+---
+
+support enum value with mix types
\ No newline at end of file
diff --git a/packages/typespec-client-generator-core/src/interfaces.ts b/packages/typespec-client-generator-core/src/interfaces.ts
index b5174d24d9..bdf9bfd1bd 100644
--- a/packages/typespec-client-generator-core/src/interfaces.ts
+++ b/packages/typespec-client-generator-core/src/interfaces.ts
@@ -329,7 +329,7 @@ export interface SdkEnumType extends SdkTypeBase {
   kind: "enum";
   name: string;
   isGeneratedName: boolean;
-  valueType: SdkBuiltInType;
+  valueType: SdkBuiltInType | SdkUnionType;
   values: SdkEnumValueType[];
   isFixed: boolean;
   isFlags: boolean;
@@ -345,7 +345,7 @@ export interface SdkEnumValueType extends SdkTypeBase {
   name: string;
   value: string | number;
   enumType: SdkEnumType;
-  valueType: SdkBuiltInType;
+  valueType: SdkBuiltInType | SdkUnionType;
 }
 
 export interface SdkConstantType extends SdkTypeBase {
diff --git a/packages/typespec-client-generator-core/src/types.ts b/packages/typespec-client-generator-core/src/types.ts
index 21b25a056c..e2947fb04c 100644
--- a/packages/typespec-client-generator-core/src/types.ts
+++ b/packages/typespec-client-generator-core/src/types.ts
@@ -788,22 +788,33 @@ export function getSdkModelWithDiagnostics(
 function getSdkEnumValueType(
   context: TCGCContext,
   values: (string | number | undefined)[]
-): [SdkBuiltInType, readonly Diagnostic[]] {
-  const diagnostics = createDiagnosticCollector();
-  let kind: "string" | "int32" | "float32" = "string";
+): SdkBuiltInType | SdkUnionType {
+  let stringType: SdkBuiltInType | undefined = undefined;
+  let numberType: SdkBuiltInType | undefined = undefined;
+
   for (const value of values) {
     if (typeof value === "number") {
-      kind = intOrFloat(value);
-      if (kind === "float32") {
-        break;
+      const calType = intOrFloat(value);
+      if (numberType === undefined || (numberType.kind === "int32" && calType === "float32")) {
+        numberType = getTypeSpecBuiltInType(context, calType);
       }
-    } else if (typeof value === "string") {
-      kind = "string";
-      break;
+    } else {
+      stringType = getTypeSpecBuiltInType(context, "string");
     }
   }
 
-  return diagnostics.wrap(getTypeSpecBuiltInType(context, kind!));
+  if (stringType === undefined || numberType === undefined) {
+    return stringType ?? numberType!;
+  } else {
+    return {
+      kind: "union",
+      values: [stringType, numberType],
+      name: "",
+      isGeneratedName: false,
+      crossLanguageDefinitionId: "",
+      decorators: [],
+    };
+  }
 }
 
 function getUnionAsEnumValueType(
@@ -874,11 +885,9 @@ function getSdkEnumWithDiagnostics(
       details: docWrapper.details,
       doc: getDoc(context.program, type),
       summary: getSummary(context.program, type),
-      valueType: diagnostics.pipe(
-        getSdkEnumValueType(
-          context,
-          [...type.members.values()].map((v) => v.value)
-        )
+      valueType: getSdkEnumValueType(
+        context,
+        [...type.members.values()].map((v) => v.value)
       ),
       values: [],
       isFixed: true, // enums are always fixed after we switch to use union to represent extensible enum
@@ -949,11 +958,9 @@ export function getSdkUnionEnumWithDiagnostics(
       summary: getSummary(context.program, union),
       valueType:
         diagnostics.pipe(getUnionAsEnumValueType(context, type.union)) ??
-        diagnostics.pipe(
-          getSdkEnumValueType(
-            context,
-            [...type.flattenedMembers.values()].map((v) => v.value)
-          )
+        getSdkEnumValueType(
+          context,
+          [...type.flattenedMembers.values()].map((v) => v.value)
         ),
       values: [],
       isFixed: !type.open,
@@ -995,11 +1002,9 @@ function getKnownValuesEnum(
         details: docWrapper.details,
         doc: getDoc(context.program, type),
         summary: getSummary(context.program, type),
-        valueType: diagnostics.pipe(
-          getSdkEnumValueType(
-            context,
-            [...knownValues.members.values()].map((v) => v.value)
-          )
+        valueType: getSdkEnumValueType(
+          context,
+          [...knownValues.members.values()].map((v) => v.value)
         ),
         values: [],
         isFixed: false,
diff --git a/packages/typespec-client-generator-core/test/types/enum-types.test.ts b/packages/typespec-client-generator-core/test/types/enum-types.test.ts
index c2ffcc4b42..57b1c76a65 100644
--- a/packages/typespec-client-generator-core/test/types/enum-types.test.ts
+++ b/packages/typespec-client-generator-core/test/types/enum-types.test.ts
@@ -793,4 +793,24 @@ describe("typespec-client-generator-core: enum types", () => {
     strictEqual(testModel.access, "public");
     strictEqual(testModel.usage, UsageFlags.Input | UsageFlags.Json);
   });
+
+  it("mix type enums", async () => {
+    await runner.compileWithBuiltInService(
+      `
+      @usage(Usage.input | Usage.output)
+      @access(Access.public)
+      enum MixTypeEnum {
+        One: 1,
+        Two: "2",
+        Three: 3.2,
+      }
+    `
+    );
+    const enums = runner.context.sdkPackage.enums;
+    strictEqual(enums.length, 1);
+    strictEqual(enums[0].name, "MixTypeEnum");
+    strictEqual(enums[0].valueType.kind, "union");
+    strictEqual(enums[0].valueType.values[0].kind, "string");
+    strictEqual(enums[0].valueType.values[1].kind, "float32");
+  });
 });