diff --git a/library/think/db/Query.php b/library/think/db/Query.php
index 9089e6ca..1032944f 100644
--- a/library/think/db/Query.php
+++ b/library/think/db/Query.php
@@ -893,7 +893,7 @@ class Query
                         } else {
                             $name = $alias . '.' . $key;
                         }
-                        $fields[]                   = $name . ' AS ' . $val;
+                        $fields[$name]              = $val;
                         $this->options['map'][$val] = $name;
                     }
                 }