diff --git a/library/think/Model.php b/library/think/Model.php
index 05f8b3cd..4419d584 100644
--- a/library/think/Model.php
+++ b/library/think/Model.php
@@ -222,9 +222,9 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
 
         // 检测字段
         if (!empty($this->field)) {
-            foreach ($data as $key => $val) {
+            foreach ($this->data as $key => $val) {
                 if (!in_array($key, $this->field)) {
-                    unset($data[$key]);
+                    unset($this->data[$key]);
                 }
             }
         }