diff --git a/app/models/attachment.rb b/app/models/attachment.rb
index 55d76ffeb..754bd4dee 100644
--- a/app/models/attachment.rb
+++ b/app/models/attachment.rb
@@ -362,8 +362,7 @@ class Attachment < ActiveRecord::Base
   #有了历史记录的数据记录是不能被删除的。
   #true 能被删除 false 不能被删除
   def destroyable
-    true
-    # self.attachment_histories.count == 0
+    self.attachment_histories.count == 0
   end
 
   # Returns file's location on disk