diff --git a/library/think/Model.php b/library/think/Model.php
index d40c6218..1a9677d4 100644
--- a/library/think/Model.php
+++ b/library/think/Model.php
@@ -169,10 +169,14 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
         $model = $this->class;
         if (!isset(self::$links[$model])) {
             // 合并数据库配置
-            if (is_array($this->connection)) {
-                $connection = array_merge(Config::get('database'), $this->connection);
+            if (!empty($this->connection)) {
+                if (is_array($this->connection)) {
+                    $connection = array_merge(Config::get('database'), $this->connection);
+                } else {
+                    $connection = $this->connection;
+                }
             } else {
-                $connection = $this->connection;
+                $connection = [];
             }
             // 设置当前模型 确保查询返回模型对象
             $query = Db::connect($connection)->model($model, $this->query);