diff --git a/library/think/Model.php b/library/think/Model.php
index 47d422e5..16db8797 100644
--- a/library/think/Model.php
+++ b/library/think/Model.php
@@ -756,7 +756,7 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
                 $value = null;
             }
             if (!in_array($field, $this->change)) {
-                $this->setAttr($field, isset($this->data[$field]) ? $this->data[$field] : $value);
+                $this->setAttr($field, !is_null($value) ? $value : (isset($this->data[$field]) ? $this->data[$field] : $value));
             }
         }
     }