diff --git a/library/think/App.php b/library/think/App.php
index 6a5b669f..6120a7b0 100644
--- a/library/think/App.php
+++ b/library/think/App.php
@@ -32,12 +32,14 @@ class App
     /**
      * 执行应用程序
      * @access public
-     * @param \think\Request $request Request对象
+     * @param null|\think\Request $request Request对象
      * @return mixed
      * @throws Exception
      */
-    public static function run($request)
+    public static function run($request = null)
     {
+        is_null($request) && $request = Request::instance();
+
         // 初始化应用（公共模块）
         $config = self::initModule(COMMON_MODULE, Config::get());
 
diff --git a/start.php b/start.php
index 9ad4264e..5ad6f069 100644
--- a/start.php
+++ b/start.php
@@ -64,5 +64,5 @@ if (APP_HOOK && isset($mode['tags'])) {
 
 // 是否自动运行
 if (APP_AUTO_RUN) {
-    App::run(Request::instance());
+    App::run();
 }