diff --git a/Think/Db.php b/Think/Db.php
index 6774fdb8..2ee97235 100644
--- a/Think/Db.php
+++ b/Think/Db.php
@@ -35,12 +35,12 @@ class Db {
             $class  =   $lite?  'Think\Db\Lite' :   'Think\\Db\\Driver\\'.ucwords($options['dbms']);
             if(class_exists($class)) {
                 self::$instance[$md5]   =   new $class($options);
-                self::$_instance        =   self::$instance[$md5];
             }else{
                 Error::halt('_DB_TYPE_INVALID_:'.$options['dbms']);
             }
         }
-        return self::$instance[$md5];
+        self::$_instance    =   self::$instance[$md5];
+        return self::$_instance;
     }
 
     /**
diff --git a/Think/Model.php b/Think/Model.php
index 5dc1410b..11af7641 100644
--- a/Think/Model.php
+++ b/Think/Model.php
@@ -781,7 +781,7 @@ class Model {
             if(!empty($config) && is_string($config) && false === strpos($config,'/')) { // 支持读取配置参数
                 $config  =  Config::get($config);
             }
-            $_db[$linkNum]            =    Db::getInstance($config);
+            $_db[$linkNum]            =    Db::instance($config);
         }elseif(NULL === $config){
             $_db[$linkNum]->close(); // 关闭数据库连接
             unset($_db[$linkNum]);