diff --git a/library/think/Model.php b/library/think/Model.php
index e92a9344..535d76a2 100644
--- a/library/think/Model.php
+++ b/library/think/Model.php
@@ -1078,6 +1078,9 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
     public function getChangedData()
     {
         $data = array_udiff_assoc($this->data, $this->origin, function ($a, $b) {
+            if ((empty($b) || empty($b)) && $a !== $b) {
+                return 1;
+            }
             return is_object($a) || $a != $b ? 1 : 0;
         });