diff --git a/library/think/Model.php b/library/think/Model.php
index d3c4d837..2160604d 100644
--- a/library/think/Model.php
+++ b/library/think/Model.php
@@ -779,22 +779,6 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
         return false;
     }
 
-    protected function autoWriteUpdateTime(&$data)
-    {
-        // 自动写入更新时间
-        if ($this->autoWriteTimestamp && $this->updateTime && (empty($this->change) || !in_array($this->updateTime, $this->change))) {
-            $data[$this->updateTime] = $this->autoWriteTimestamp($this->updateTime);
-        }
-    }
-
-    protected function autoWriteCreateTime(&$data)
-    {
-        // 自动写入创建时间
-        if ($this->autoWriteTimestamp && $this->createTime && (empty($this->change) || !in_array($this->createTime, $this->change))) {
-            $data[$this->createTime] = $this->autoWriteTimestamp($this->createTime);
-        }
-    }
-
     /**
      * 保存当前数据对象
      * @access public
@@ -886,9 +870,9 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
                 }
             }
 
-            if (!empty($data)) {
+            if (!empty($data) && $this->autoWriteTimestamp && $this->updateTime && !isset($data[$this->updateTime])) {
                 // 自动写入更新时间
-                $this->autoWriteUpdateTime($data);
+                $data[$this->updateTime] = $this->autoWriteTimestamp($this->updateTime);
             } else {
                 return 0;
             }
@@ -939,10 +923,15 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
         } else {
             // 自动写入
             $this->autoCompleteData($this->insert);
-            // 自动写入创建时间
-            $this->autoWriteCreateTime($this->data);
-            // 自动写入更新时间
-            $this->autoWriteUpdateTime($this->data);
+            // 自动写入创建时间和更新时间
+            if ($this->autoWriteTimestamp) {
+                if ($this->createTime && !isset($this->data[$this->createTime])) {
+                    $this->data[$this->createTime] = $this->autoWriteTimestamp($this->createTime);
+                }
+                if ($this->updateTime && !isset($this->data[$this->updateTime])) {
+                    $this->data[$this->updateTime] = $this->autoWriteTimestamp($this->updateTime);
+                }
+            }
 
             if (false === $this->trigger('before_insert', $this)) {
                 return false;