diff --git a/src/app/service/extension/extension_env.test.ts b/src/app/service/extension/extension_env.test.ts
index 768d59724..a464a05de 100644
--- a/src/app/service/extension/extension_env.test.ts
+++ b/src/app/service/extension/extension_env.test.ts
@@ -1,5 +1,5 @@
 import { afterEach, describe, expect, it, vi } from "vitest";
-import { extensionEnv, getExtensionUserAgentData } from "./extension_env";
+import { extensionEnv, getExtensionEnv, getExtensionUserAgentData } from "./extension_env";
 
 describe("extensionEnv 常量", () => {
   it("读取扩展上下文状态与 manifest 的 incognito 模式", () => {
@@ -10,6 +10,17 @@ describe("extensionEnv 常量", () => {
     // userAgentData 为可选字段，常量初始化时不应填充
     expect(extensionEnv.userAgentData).toBeUndefined();
   });
+
+  it("chrome.extension 缺失时仍能初始化环境并默认非隐身", () => {
+    const originalExtension = (chrome as any).extension;
+    try {
+      delete (chrome as any).extension;
+      expect(() => getExtensionEnv()).not.toThrow();
+      expect(getExtensionEnv().inIncognitoContext).toBe(false);
+    } finally {
+      (chrome as any).extension = originalExtension;
+    }
+  });
 });
 
 describe("getExtensionUserAgentData", () => {
diff --git a/src/app/service/extension/extension_env.ts b/src/app/service/extension/extension_env.ts
index c033c07ce..46c8052e7 100644
--- a/src/app/service/extension/extension_env.ts
+++ b/src/app/service/extension/extension_env.ts
@@ -6,10 +6,12 @@ export type TExtensionEnv = {
 
 type GMUserAgentData = typeof GM_info.userAgentData;
 
-export const extensionEnv: TExtensionEnv = {
-  inIncognitoContext: chrome.extension.inIncognitoContext,
+export const getExtensionEnv = (): TExtensionEnv => ({
+  inIncognitoContext: chrome.extension?.inIncognitoContext ?? false,
   incognitoMode: chrome.runtime.getManifest().incognito,
-} satisfies TExtensionEnv;
+});
+
+export const extensionEnv: TExtensionEnv = getExtensionEnv();
 
 export const getExtensionUserAgentData = async (): Promise<GMUserAgentData | null> => {
   // @ts-ignore
diff --git a/src/app/service/service_worker/runtime.test.ts b/src/app/service/service_worker/runtime.test.ts
index 27103b47c..337fbd137 100644
--- a/src/app/service/service_worker/runtime.test.ts
+++ b/src/app/service/service_worker/runtime.test.ts
@@ -1,6 +1,6 @@
 import { initTestEnv } from "@Tests/utils";
 import { RuntimeService } from "./runtime";
-import { vi, describe, it, expect, beforeEach, type MockedFunction } from "vitest";
+import { vi, describe, it, expect, beforeEach, afterEach, type MockedFunction } from "vitest";
 import { randomUUID } from "crypto";
 import type { Script, ScriptRunResource } from "@App/app/repo/scripts";
 import {
@@ -1192,3 +1192,63 @@ describe("MQ 事件处理效果（enableScripts / deleteScripts / sortedScripts
     expect((runtime as any).cachedPatterns.has(uuid)).toBe(false);
   });
 });
+
+describe("registerUserscripts 注册健康检查", () => {
+  let runtime: RuntimeService;
+  let originalScripting: unknown;
+
+  beforeEach(() => {
+    runtime = _createRuntimeContext().runtime;
+    originalScripting = (chrome as any).scripting;
+    (chrome as any).scripting = {
+      getRegisteredContentScripts: vi.fn().mockResolvedValue([{ id: "scriptcat-scripting" }]),
+      registerContentScripts: vi.fn().mockResolvedValue(undefined),
+      unregisterContentScripts: vi.fn().mockResolvedValue(undefined),
+    };
+    vi.spyOn(chrome.userScripts as any, "getScripts").mockResolvedValue([{ id: "scriptcat-inject" }]);
+    vi.spyOn(chrome.userScripts, "register").mockResolvedValue(undefined);
+    vi.spyOn(chrome.userScripts, "resetWorldConfiguration").mockResolvedValue(undefined);
+    vi.spyOn(runtime, "unregisterUserscripts").mockResolvedValue(undefined);
+    vi.spyOn(runtime as any, "getParticularScriptList").mockResolvedValue([]);
+    vi.spyOn(runtime as any, "getContentAndInjectScript").mockResolvedValue({ content: [], inject: [] });
+    runtime.isUserScriptsAvailable = true;
+  });
+
+  afterEach(async () => {
+    vi.restoreAllMocks();
+    await runtime.unregisterUserscripts();
+    (chrome as any).scripting = originalScripting;
+  });
+
+  const primeRegisteredState = async () => {
+    await runtime.registerUserscripts();
+    vi.clearAllMocks();
+  };
+
+  it("已注册用户脚本但 scripting 广播者丢失时重新注册", async () => {
+    await primeRegisteredState();
+    (chrome as any).scripting.getRegisteredContentScripts.mockResolvedValue([]);
+
+    await runtime.registerUserscripts();
+
+    expect(chrome.userScripts.getScripts).toHaveBeenCalledWith({ ids: ["scriptcat-inject"] });
+    expect((chrome as any).scripting.getRegisteredContentScripts).toHaveBeenCalledWith({
+      ids: ["scriptcat-scripting"],
+    });
+    expect(runtime.unregisterUserscripts).toHaveBeenCalled();
+    expect(chrome.userScripts.register).toHaveBeenCalled();
+  });
+
+  it("用户脚本和 scripting 广播者都在时跳过重复注册", async () => {
+    await primeRegisteredState();
+
+    await runtime.registerUserscripts();
+
+    expect(chrome.userScripts.getScripts).toHaveBeenCalledWith({ ids: ["scriptcat-inject"] });
+    expect((chrome as any).scripting.getRegisteredContentScripts).toHaveBeenCalledWith({
+      ids: ["scriptcat-scripting"],
+    });
+    expect(runtime.unregisterUserscripts).not.toHaveBeenCalled();
+    expect(chrome.userScripts.register).not.toHaveBeenCalled();
+  });
+});
diff --git a/src/app/service/service_worker/runtime.ts b/src/app/service/service_worker/runtime.ts
index ca06143f1..ca12ff556 100644
--- a/src/app/service/service_worker/runtime.ts
+++ b/src/app/service/service_worker/runtime.ts
@@ -1078,7 +1078,8 @@ export class RuntimeService {
       // 异常情况
       // 检查scriptcat-content和scriptcat-inject是否存在
       const res = await chrome.userScripts.getScripts({ ids: ["scriptcat-inject"] });
-      if (res.length === 1) {
+      const contentScripts = await chrome.scripting.getRegisteredContentScripts({ ids: ["scriptcat-scripting"] });
+      if (res.length === 1 && contentScripts.length === 1) {
         return;
       }
       // scriptcat-content/scriptcat-inject不存在的情况