diff --git a/src/plugins/markdown/command/__tests__/command.test.ts b/src/plugins/markdown/command/__tests__/command.test.ts
index bfda4de5..41c6013b 100644
--- a/src/plugins/markdown/command/__tests__/command.test.ts
+++ b/src/plugins/markdown/command/__tests__/command.test.ts
@@ -12,14 +12,18 @@ import {
   MentionPlugin,
   TablePlugin,
 } from '@lobehub/editor';
-import { REDO_COMMAND, UNDO_COMMAND } from 'lexical';
-import { describe, expect, it } from 'vitest';
+import { COPY_COMMAND, REDO_COMMAND, UNDO_COMMAND } from 'lexical';
+import { afterEach, describe, expect, it, vi } from 'vitest';
 
 import Editor from '@/editor-kernel';
 
 import { MarkdownPlugin } from '../../plugin';
 import { GET_MARKDOWN_SELECTION_COMMAND, INSERT_MARKDOWN_COMMAND } from '../index';
 
+afterEach(() => {
+  vi.unstubAllGlobals();
+});
+
 const json = {
   root: {
     children: [
@@ -496,6 +500,174 @@ const json = {
 };
 
 describe('Markdown Commands', () => {
+  describe('COPY_COMMAND', () => {
+    const dispatchCopyCommand = (editor: ReturnType<typeof Editor.createEditor>) => {
+      const clipboard = new Map<string, string>();
+      const clipboardData = {
+        clearData: (type?: string) => {
+          if (type) {
+            clipboard.delete(type);
+          } else {
+            clipboard.clear();
+          }
+        },
+        getData: (type: string) => clipboard.get(type) || '',
+        setData: (type: string, value: string) => {
+          clipboard.set(type, value);
+        },
+        get types() {
+          return Array.from(clipboard.keys());
+        },
+      } as unknown as DataTransfer;
+      class MockClipboardEvent extends Event {
+        clipboardData = clipboardData;
+      }
+      vi.stubGlobal('ClipboardEvent', MockClipboardEvent);
+
+      const event = new MockClipboardEvent('copy') as ClipboardEvent;
+
+      editor.dispatchCommand(COPY_COMMAND, event);
+
+      return clipboard;
+    };
+
+    it('should write a partial paragraph selection without formatter-generated trailing line break', async () => {
+      const editor = Editor.createEditor().registerPlugins([CommonPlugin, MarkdownPlugin]);
+      editor.initNodeEditor();
+
+      editor.setDocument(
+        'json',
+        {
+          root: {
+            children: [
+              {
+                children: [
+                  {
+                    detail: 0,
+                    format: 0,
+                    id: '2',
+                    mode: 'normal',
+                    style: '',
+                    text: 'before js代码 after',
+                    type: 'text',
+                    version: 1,
+                  },
+                ],
+                direction: 'ltr',
+                format: '',
+                id: '1',
+                indent: 0,
+                textFormat: 0,
+                textStyle: '',
+                type: 'paragraph',
+                version: 1,
+              },
+            ],
+            direction: 'ltr',
+            format: '',
+            id: 'root',
+            indent: 0,
+            type: 'root',
+            version: 1,
+          },
+        },
+        { keepId: true },
+      );
+
+      await editor.setSelection({
+        endNodeId: '2',
+        endOffset: 11,
+        startNodeId: '2',
+        startOffset: 7,
+        type: 'range',
+      });
+
+      const clipboard = dispatchCopyCommand(editor);
+
+      expect(clipboard.get('text/plain')).toBe('js代码');
+      expect(clipboard.get('text/markdown')).toBe('js代码');
+    });
+
+    it('should preserve paragraph breaks when copying across paragraphs', async () => {
+      const editor = Editor.createEditor().registerPlugins([CommonPlugin, MarkdownPlugin]);
+      editor.initNodeEditor();
+
+      editor.setDocument(
+        'json',
+        {
+          root: {
+            children: [
+              {
+                children: [
+                  {
+                    detail: 0,
+                    format: 0,
+                    id: '2',
+                    mode: 'normal',
+                    style: '',
+                    text: 'before 第一段',
+                    type: 'text',
+                    version: 1,
+                  },
+                ],
+                direction: 'ltr',
+                format: '',
+                id: '1',
+                indent: 0,
+                textFormat: 0,
+                textStyle: '',
+                type: 'paragraph',
+                version: 1,
+              },
+              {
+                children: [
+                  {
+                    detail: 0,
+                    format: 0,
+                    id: '4',
+                    mode: 'normal',
+                    style: '',
+                    text: '第二段 after',
+                    type: 'text',
+                    version: 1,
+                  },
+                ],
+                direction: 'ltr',
+                format: '',
+                id: '3',
+                indent: 0,
+                textFormat: 0,
+                textStyle: '',
+                type: 'paragraph',
+                version: 1,
+              },
+            ],
+            direction: 'ltr',
+            format: '',
+            id: 'root',
+            indent: 0,
+            type: 'root',
+            version: 1,
+          },
+        },
+        { keepId: true },
+      );
+
+      await editor.setSelection({
+        endNodeId: '4',
+        endOffset: 3,
+        startNodeId: '2',
+        startOffset: 7,
+        type: 'range',
+      });
+
+      const clipboard = dispatchCopyCommand(editor);
+
+      expect(clipboard.get('text/plain')).toBe('第一段\n\n第二段');
+      expect(clipboard.get('text/markdown')).toBe('第一段\n\n第二段');
+    });
+  });
+
   describe('INSERT_MARKDOWN_COMMAND', () => {
     it('should keep markdown auto-convert redoable after undo', async () => {
       const editor = Editor.createEditor().registerPlugins([CommonPlugin, MarkdownPlugin]);
diff --git a/src/plugins/markdown/plugin/__tests__/paste.test.ts b/src/plugins/markdown/plugin/__tests__/paste.test.ts
index c9a3f500..1d8d3089 100644
--- a/src/plugins/markdown/plugin/__tests__/paste.test.ts
+++ b/src/plugins/markdown/plugin/__tests__/paste.test.ts
@@ -1,6 +1,6 @@
 import { describe, expect, it, vi } from 'vitest';
 
-import { MarkdownPlugin } from '../index';
+import { MarkdownPlugin, normalizeMarkdownForClipboard } from '../index';
 
 const createKernelMock = () =>
   ({
@@ -120,3 +120,14 @@ describe('Markdown paste auto conversion', () => {
     expect(result).toBe(false);
   });
 });
+
+describe('Markdown copy normalization', () => {
+  it('should remove the formatter-generated trailing line break from copied plain text', () => {
+    expect(normalizeMarkdownForClipboard('js代码\n')).toBe('js代码');
+    expect(normalizeMarkdownForClipboard('js代码\r\n')).toBe('js代码');
+  });
+
+  it('should preserve non-line-break trailing whitespace while copying', () => {
+    expect(normalizeMarkdownForClipboard('js代码  \n')).toBe('js代码  ');
+  });
+});
diff --git a/src/plugins/markdown/plugin/index.ts b/src/plugins/markdown/plugin/index.ts
index fc3d470b..710a5e81 100644
--- a/src/plugins/markdown/plugin/index.ts
+++ b/src/plugins/markdown/plugin/index.ts
@@ -45,6 +45,8 @@ interface MarkdownDetectionResult {
 const RICH_HTML_SELECTOR =
   'strong,em,b,i,h1,h2,h3,h4,h5,h6,ul,ol,table,img,blockquote,pre>code,a[href]';
 
+export const normalizeMarkdownForClipboard = (markdown: string) => markdown.replace(/\r?\n$/, '');
+
 const MARKDOWN_DETECTION_RULES = [
   { name: 'headers', score: 5, test: (text) => /^#{1,6}\s+\S/m.test(text) },
   { name: 'code-fence-start', score: 5, test: (text) => /^```[\w-]*$/m.test(text) },
@@ -324,8 +326,10 @@ export const MarkdownPlugin: IEditorPluginConstructor<MarkdownPluginOptions> = c
           if (!selection || selection.isCollapsed()) return false;
 
           // Get the selection as markdown
-          const markdown = this.markdownDataSource.write(editor, { selection: true });
-          if (!markdown) return false;
+          const rawMarkdown = this.markdownDataSource.write(editor, { selection: true });
+          if (!rawMarkdown) return false;
+
+          const markdown = normalizeMarkdownForClipboard(rawMarkdown);
 
           event.preventDefault();