diff --git a/muse-studio/src/api/mocks/handlers/content.ts b/muse-studio/src/api/mocks/handlers/content.ts
index 9a510485..3d1564f5 100644
--- a/muse-studio/src/api/mocks/handlers/content.ts
+++ b/muse-studio/src/api/mocks/handlers/content.ts
@@ -48,6 +48,19 @@ interface BlockSaveRequest {
   };
 }
 
+/** split/merge 结构编辑命令(mock 入参)。 */
+interface BlockStructureRequest {
+  commandId?: string;
+  splitPosition?: number;
+  targetBlockId?: string;
+  expectedRevision?: number;
+  sourceSnapshot?: {
+    contentRevision?: number;
+    sourceType?: string;
+    sourceId?: string;
+  };
+}
+
 interface TiptapTextNode {
   text?: string;
   content?: TiptapTextNode[];
@@ -84,6 +97,29 @@ function createChapterContent(title: string, wordCount: number): string {
   });
 }
 
+/** 构造符合 Block 契约的 mock 对象(对齐 chapterDetail handler 的 block 结构),供 split/merge 返回。 */
+function mockBlock(id: string, chapter: MockChapter, content: string, sortOrder: number, version: number) {
+  const textNodes: string[] = [];
+  try {
+    collectTiptapText(JSON.parse(content), textNodes);
+  } catch {
+    /* 正文非合法 JSON 时字数计 0,不阻断 mock。 */
+  }
+  return {
+    id,
+    workId: chapter.workId,
+    chapterId: chapter.id,
+    blockType: 'scene',
+    title: chapter.title,
+    content,
+    sortOrder,
+    version,
+    wordCount: textNodes.join('').length,
+    createdAt: '2026-05-20T00:00:00Z',
+    updatedAt: new Date().toISOString(),
+  };
+}
+
 /** 构造章节和首个正文 Block 的一体化 mock 数据。 */
 function createMockChapter(
   id: string,
@@ -526,4 +562,59 @@ export const contentHandlers = [
       },
     });
   }),
+
+  // POST /app-api/muse/works/:workId/blocks/:blockId/split — 分割 Block(mock:校验乐观锁后返回原+新两个 Block)
+  http.post('/app-api/muse/works/:workId/blocks/:blockId/split', async ({ params, request }) => {
+    const { workId, blockId } = params;
+    const body = (await request.json()) as BlockStructureRequest;
+    const chapter = mockChapters.find((ch) => ch.blockId === blockId && ch.workId === workId);
+
+    if (!chapter) {
+      return HttpResponse.json({ code: 40403, msg: 'Block 不存在', data: null }, { status: 404 });
+    }
+    if (!body.commandId || !body.sourceSnapshot) {
+      return HttpResponse.json({ code: 40001, msg: '缺少分割命令字段', data: null }, { status: 400 });
+    }
+    if (body.expectedRevision !== chapter.blockVersion) {
+      return HttpResponse.json({ code: 40901, msg: 'Block 版本已变化，请刷新后重试', data: null }, { status: 409 });
+    }
+
+    // mock 不持久化多 Block(单 Block 模型),仅校验后返回符合契约的两个 Block;真实多 Block 由真后端 e2e 覆盖。
+    chapter.blockVersion += 1;
+    const newBlockId = crypto.randomUUID();
+    return HttpResponse.json({
+      code: 0,
+      msg: 'success',
+      data: {
+        originalBlock: mockBlock(chapter.blockId, chapter, chapter.content, 1, chapter.blockVersion),
+        newBlock: mockBlock(newBlockId, chapter, createChapterContent(chapter.title, 0), 2, 1),
+      },
+    });
+  }),
+
+  // POST /app-api/muse/works/:workId/blocks/:blockId/merge — 合并 Block(mock:校验乐观锁后返回合并后 Block)
+  http.post('/app-api/muse/works/:workId/blocks/:blockId/merge', async ({ params, request }) => {
+    const { workId, blockId } = params;
+    const body = (await request.json()) as BlockStructureRequest;
+    const chapter = mockChapters.find((ch) => ch.blockId === blockId && ch.workId === workId);
+
+    if (!chapter) {
+      return HttpResponse.json({ code: 40403, msg: 'Block 不存在', data: null }, { status: 404 });
+    }
+    if (!body.commandId || !body.sourceSnapshot) {
+      return HttpResponse.json({ code: 40001, msg: '缺少合并命令字段', data: null }, { status: 400 });
+    }
+    if (body.expectedRevision !== chapter.blockVersion) {
+      return HttpResponse.json({ code: 40901, msg: 'Block 版本已变化，请刷新后重试', data: null }, { status: 409 });
+    }
+
+    chapter.blockVersion += 1;
+    return HttpResponse.json({
+      code: 0,
+      msg: 'success',
+      data: {
+        mergedBlock: mockBlock(chapter.blockId, chapter, chapter.content, 1, chapter.blockVersion),
+      },
+    });
+  }),
 ];
diff --git a/muse-studio/src/features/editor/hooks/useBlockStructure.test.tsx b/muse-studio/src/features/editor/hooks/useBlockStructure.test.tsx
new file mode 100644
index 00000000..76a3c58a
--- /dev/null
+++ b/muse-studio/src/features/editor/hooks/useBlockStructure.test.tsx
@@ -0,0 +1,44 @@
+import { describe, it, expect, beforeEach } from 'vitest';
+import { renderHook, waitFor } from '@testing-library/react';
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
+import { useSplitBlock, useMergeBlock } from './useBlockStructure';
+import { resetMockDb } from '@/api/mocks/handlers/content';
+import React from 'react';
+
+const createTestQueryClient = () =>
+  new QueryClient({
+    defaultOptions: { queries: { retry: false, gcTime: 0 }, mutations: { retry: false } },
+  });
+
+const wrapper = ({ children }: { children: React.ReactNode }) => {
+  const queryClient = createTestQueryClient();
+  return <QueryClientProvider client={queryClient}>{children}</QueryClientProvider>;
+};
+
+describe('useBlockStructure (split/merge) hooks 单元测试', () => {
+  beforeEach(() => {
+    resetMockDb();
+  });
+
+  it('useSplitBlock 分割后应返回原 Block 与新 Block', async () => {
+    const { result } = renderHook(() => useSplitBlock('1', '1-1'), { wrapper });
+    result.current.mutate({ blockId: 'block-1-1-main', splitPosition: 5, expectedRevision: 1 });
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+    expect(result.current.data?.originalBlock.id).toBe('block-1-1-main');
+    expect(result.current.data?.newBlock.id).toBeTruthy();
+    expect(result.current.data?.newBlock.id).not.toBe('block-1-1-main'); // 新 Block 独立 id。
+  });
+
+  it('useMergeBlock 合并后应返回合并 Block', async () => {
+    const { result } = renderHook(() => useMergeBlock('1', '1-1'), { wrapper });
+    result.current.mutate({ blockId: 'block-1-1-main', expectedRevision: 1 });
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+    expect(result.current.data?.mergedBlock.id).toBe('block-1-1-main');
+  });
+
+  it('useSplitBlock 乐观锁版本不匹配应失败(409)', async () => {
+    const { result } = renderHook(() => useSplitBlock('1', '1-1'), { wrapper });
+    result.current.mutate({ blockId: 'block-1-1-main', splitPosition: 5, expectedRevision: 999 });
+    await waitFor(() => expect(result.current.isError).toBe(true));
+  });
+});
diff --git a/muse-studio/src/features/editor/hooks/useBlockStructure.ts b/muse-studio/src/features/editor/hooks/useBlockStructure.ts
new file mode 100644
index 00000000..d930ddfb
--- /dev/null
+++ b/muse-studio/src/features/editor/hooks/useBlockStructure.ts
@@ -0,0 +1,77 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+import { api } from '@/api/client';
+import type { BlockVO, SplitBlockRequest, MergeBlockRequest } from '@/types/openapi';
+
+/**
+ * Block 结构编辑(分割/合并)的 mutation hooks。
+ *
+ * OpenAPI 将 split/merge 的 200 response 误声明为 content:never(后端 response schema 注解缺失),
+ * 实际后端返回 SplitBlockRespVO{originalBlock,newBlock} / MergeBlockRespVO{mergedBlock},故此处手写 Result。
+ * 成功后失效章节详情(['chapterDetail',chapterId])与大纲(['chapterList',workId]),触发多 Block 列表重拉。
+ */
+
+/** 分割结果:原 Block(前半)+新 Block(后半)。 */
+export interface SplitBlockResult {
+  originalBlock: BlockVO;
+  newBlock: BlockVO;
+}
+
+/** 合并结果:合并后的 Block。 */
+export interface MergeBlockResult {
+  mergedBlock: BlockVO;
+}
+
+/** 分割 Block:在 splitPosition(字符偏移)处把一个 Block 切成两个。 */
+export function useSplitBlock(workId: string, chapterId: string) {
+  const queryClient = useQueryClient();
+  return useMutation({
+    mutationFn: ({
+      blockId,
+      splitPosition,
+      expectedRevision,
+    }: {
+      blockId: string;
+      splitPosition: number;
+      expectedRevision: number;
+    }) =>
+      api.post<SplitBlockResult>(`/works/${workId}/blocks/${blockId}/split`, {
+        commandId: crypto.randomUUID(),
+        splitPosition,
+        expectedRevision,
+        sourceSnapshot: { sourceType: 'user_original', sourceId: blockId, contentRevision: expectedRevision },
+      } satisfies SplitBlockRequest),
+    onSuccess: () => {
+      // 分割后章节内 Block 数量变化,失效详情与大纲缓存触发重拉。
+      queryClient.invalidateQueries({ queryKey: ['chapterDetail', chapterId] });
+      queryClient.invalidateQueries({ queryKey: ['chapterList', workId] });
+    },
+  });
+}
+
+/** 合并 Block:把当前 Block 与目标相邻 Block(targetBlockId 不传时后端默认与下一个合并)合为一个。 */
+export function useMergeBlock(workId: string, chapterId: string) {
+  const queryClient = useQueryClient();
+  return useMutation({
+    mutationFn: ({
+      blockId,
+      targetBlockId,
+      expectedRevision,
+    }: {
+      blockId: string;
+      targetBlockId?: string;
+      expectedRevision: number;
+    }) =>
+      api.post<MergeBlockResult>(`/works/${workId}/blocks/${blockId}/merge`, {
+        commandId: crypto.randomUUID(),
+        expectedRevision,
+        // targetBlockId 为可选(exactOptionalPropertyTypes 禁显式 undefined):仅指定时带上,不传则后端默认与下一个 Block 合并。
+        ...(targetBlockId ? { targetBlockId } : {}),
+        sourceSnapshot: { sourceType: 'user_original', sourceId: blockId, contentRevision: expectedRevision },
+      } satisfies MergeBlockRequest),
+    onSuccess: () => {
+      // 合并后章节内 Block 数量变化,失效详情与大纲缓存触发重拉。
+      queryClient.invalidateQueries({ queryKey: ['chapterDetail', chapterId] });
+      queryClient.invalidateQueries({ queryKey: ['chapterList', workId] });
+    },
+  });
+}
diff --git a/muse-studio/src/types/openapi.ts b/muse-studio/src/types/openapi.ts
index 8f0f8ee3..cb24bfb1 100644
--- a/muse-studio/src/types/openapi.ts
+++ b/muse-studio/src/types/openapi.ts
@@ -54,3 +54,7 @@ export type MetaProjectionSummary = ContentComponents['schemas']['MetaProjection
 export type MetaProjectionDetail = ContentComponents['schemas']['MetaProjectionDetail'];
 export type DynamicFieldValidationRequest = ContentComponents['schemas']['DynamicFieldValidationRequest'];
 export type DynamicFieldValidationResult = ContentComponents['schemas']['DynamicFieldValidationResult'];
+// Block 结构编辑(split/merge)——Request 取自 openapi;OpenAPI 误将 200 response 声明为 content:never
+// (后端 response schema 注解缺失),故 Result 在 useBlockStructure 内手写(对齐后端 SplitBlockRespVO/MergeBlockRespVO)。
+export type SplitBlockRequest = ContentComponents['schemas']['SplitBlockRequest'];
+export type MergeBlockRequest = ContentComponents['schemas']['MergeBlockRequest'];