diff --git a/muse-studio/e2e/block-structure.spec.ts b/muse-studio/e2e/block-structure.spec.ts
new file mode 100644
index 00000000..31272cad
--- /dev/null
+++ b/muse-studio/e2e/block-structure.spec.ts
@@ -0,0 +1,43 @@
+import { expect, test, type Page } from '@playwright/test';
+
+/**
+ * Block 分割/合并端到端(真实后端,MSW off)。
+ *
+ * 覆盖 D 链路:进 work1 workspace → BlockStructureBar 显示章节结构 → 分割首节(真实 split,1→2)→
+ * 验证 2 个小节 → 合并首节与下一节(真实 merge,2→1)→ 验证回到 1 个小节。
+ * globalSetup 已复位 work1 chapter1 为单 Block(幂等:即使中途失败残留也清掉)。
+ */
+const TOKEN = 'test1';
+
+async function seedToken(page: Page): Promise<void> {
+  await page.addInitScript((t) => {
+    window.localStorage.setItem('accessToken', t);
+    window.localStorage.setItem('tenantId', '1');
+  }, TOKEN);
+}
+
+test('用户分割与合并章节内 Block(真实后端结构编辑)', async ({ page }) => {
+  await seedToken(page);
+
+  await page.goto('/workspace/1');
+  await expect(page.getByRole('heading', { name: /正在创作/ })).toBeVisible({ timeout: 15_000 });
+
+  // 章节结构条出现,初始 1 个小节(globalSetup 已复位)。
+  await expect(page.getByText(/章节结构 · 1 个小节/)).toBeVisible({ timeout: 15_000 });
+
+  // 分割首节(真实 split)→ chapterDetail 重拉 → 2 个小节。
+  const splitResp = page.waitForResponse(
+    (r) => /\/blocks\/[^/]+\/split/.test(r.url()) && r.request().method() === 'POST'
+  );
+  await page.getByRole('button', { name: '分割小节 1' }).click();
+  expect((await splitResp).status()).toBe(200);
+  await expect(page.getByText(/章节结构 · 2 个小节/)).toBeVisible({ timeout: 10_000 });
+
+  // 合并首节与下一节(真实 merge)→ 回到 1 个小节。
+  const mergeResp = page.waitForResponse(
+    (r) => /\/blocks\/[^/]+\/merge/.test(r.url()) && r.request().method() === 'POST'
+  );
+  await page.getByRole('button', { name: '合并小节 1 与下一节' }).click();
+  expect((await mergeResp).status()).toBe(200);
+  await expect(page.getByText(/章节结构 · 1 个小节/)).toBeVisible({ timeout: 10_000 });
+});
diff --git a/muse-studio/e2e/global-setup.ts b/muse-studio/e2e/global-setup.ts
index 018404ee..75cc1e22 100644
--- a/muse-studio/e2e/global-setup.ts
+++ b/muse-studio/e2e/global-setup.ts
@@ -223,7 +223,14 @@ async function globalSetup(): Promise<void> {
     // work1 绑 setting(其 target_type=novel_work → 投影列出同 targetType 的 setting+worldview)。
     await client.query('UPDATE muse_content_work SET work_schema_id=$1 WHERE tenant_id=1 AND id=1', [settingSchemaId]);
 
-    console.log('[e2e globalSetup] 已复位每轮 fixture(graph/confirm-draft/accept/security-ack/appeal/binding/meta-schema)');
+    // 8) block split/merge:复位 work1 chapter1 为单 Block——删 split 残留的多余 Block(保留 order_no 最小的首 Block),
+    //    供 D block 结构编辑 e2e 幂等重跑(split→2→merge→1,中途失败的残留也清掉)。
+    await client.query(
+      `DELETE FROM muse_content_block WHERE tenant_id=1 AND work_id=1 AND chapter_id=1
+         AND id <> (SELECT id FROM muse_content_block WHERE tenant_id=1 AND work_id=1 AND chapter_id=1 ORDER BY order_no, id LIMIT 1)`
+    );
+
+    console.log('[e2e globalSetup] 已复位每轮 fixture(graph/confirm-draft/accept/security-ack/appeal/binding/meta-schema/block)');
   } finally {
     await client.end();
   }
diff --git a/muse-studio/src/features/editor/components/BlockStructureBar.tsx b/muse-studio/src/features/editor/components/BlockStructureBar.tsx
index 1763558b..22941bf6 100644
--- a/muse-studio/src/features/editor/components/BlockStructureBar.tsx
+++ b/muse-studio/src/features/editor/components/BlockStructureBar.tsx
@@ -1,8 +1,8 @@
 import { useSplitBlock, useMergeBlock } from '../hooks/useBlockStructure';
 import type { BlockVO } from '@/types/openapi';
 
-/** 从 Tiptap JSON 字符串提取纯文本(用于摘要 + 计算分割中点)。 */
-function extractText(contentJson: string): string {
+/** 从正文提取纯文本(用于摘要 + 计算分割中点);兼容 Tiptap JSON 与纯文本 content(基础种子可能是纯文本)。 */
+function extractText(content: string): string {
   try {
     const out: string[] = [];
     const walk = (node: unknown): void => {
@@ -11,10 +11,11 @@ function extractText(contentJson: string): string {
       if (typeof n.text === 'string') out.push(n.text);
       if (Array.isArray(n.content)) n.content.forEach(walk);
     };
-    walk(JSON.parse(contentJson));
-    return out.join('');
+    walk(JSON.parse(content));
+    const joined = out.join('');
+    return joined || content; // 是 JSON 但无文本节点 → 退回原串。
   } catch {
-    return '';
+    return content; // content 非 JSON(纯文本)→ 直接用。
   }
 }