diff --git a/library/think/Loader.php b/library/think/Loader.php
index be74b333..c2c96f49 100644
--- a/library/think/Loader.php
+++ b/library/think/Loader.php
@@ -49,12 +49,6 @@ class Loader
             if (isset(self::$namespace[$name])) {
                 // 注册的命名空间
                 $path = self::$namespace[$name];
-            } elseif (in_array($name, ['think', 'behavior', 'traits']) || is_dir(LIB_PATH . $name)) {
-                // 核心类库命名空间
-                $path = LIB_PATH . $name . DS;
-            } elseif (APP_NAMESPACE == $name) {
-                // 项目命名空间
-                $path = APP_PATH;
             } elseif (is_dir(EXTEND_PATH . $name)) {
                 // 扩展类库命名空间
                 $path = EXTEND_PATH . $name . DS;
diff --git a/mode/common.php b/mode/common.php
index 5f02d2d3..3879e1ff 100644
--- a/mode/common.php
+++ b/mode/common.php
@@ -47,4 +47,12 @@ return [
         'think\cache\driver\File'    => CORE_PATH . 'cache' . DS . 'driver' . DS . 'File' . EXT,
     ],
 
+    // 命名空间
+    'namespace' => [
+            'think'         => LIB_PATH . 'think' . DS,
+            'behavior'      => LIB_PATH . 'behavior' . DS,
+            'traits'        => LIB_PATH . 'traits' . DS,
+            APP_NAMESPACE   => APP_PATH,
+    ],
+
 ];
diff --git a/mode/console.php b/mode/console.php
index 2a35e7c7..82c46c5e 100644
--- a/mode/console.php
+++ b/mode/console.php
@@ -17,6 +17,14 @@ return [
 
     'config' => [
         'commands' => []
-    ]
+    ],
+
+    // 命名空间
+    'namespace' => [
+            'think'         => LIB_PATH . 'think' . DS,
+            'behavior'      => LIB_PATH . 'behavior' . DS,
+            'traits'        => LIB_PATH . 'traits' . DS,
+            APP_NAMESPACE   => APP_PATH,
+    ],
 
 ];
diff --git a/mode/sae.php b/mode/sae.php
index 2a1bdbe7..ff3aba1f 100644
--- a/mode/sae.php
+++ b/mode/sae.php
@@ -96,4 +96,12 @@ return [
         'think\template\driver\Sae'  => CORE_PATH . 'template' . DS . 'driver' . DS . 'Sae' . EXT,
     ],
 
+    // 命名空间
+    'namespace' => [
+            'think'         => LIB_PATH . 'think' . DS,
+            'behavior'      => LIB_PATH . 'behavior' . DS,
+            'traits'        => LIB_PATH . 'traits' . DS,
+            APP_NAMESPACE   => APP_PATH,
+    ],
+
 ];
diff --git a/start.php b/start.php
index 8c6f8329..ce9ebbb8 100644
--- a/start.php
+++ b/start.php
@@ -19,17 +19,22 @@ require CORE_PATH . 'Loader.php';
 // 注册自动加载
 Loader::register();
 
-// 注册错误和异常处理机制
-Error::register();
-
 // 加载模式定义文件
 $mode = require MODE_PATH . APP_MODE . EXT;
 
+// 加载空间别名定义
+if (isset($mode['namespace'])) {
+    Loader::addNamespace(is_array($mode['namespace']) ? $mode['namespace'] : include $mode['namespace']);
+}
+
 // 加载模式别名定义
 if (isset($mode['alias'])) {
     Loader::addMap(is_array($mode['alias']) ? $mode['alias'] : include $mode['alias']);
 }
 
+// 注册错误和异常处理机制
+Error::register();
+
 // 加载模式配置文件
 if (isset($mode['config'])) {
     is_array($mode['config']) ? Config::set($mode['config']) : Config::load($mode['config']);