diff --git a/app/models/homework_common.rb b/app/models/homework_common.rb
index d55973ed8..c0882ec6f 100644
--- a/app/models/homework_common.rb
+++ b/app/models/homework_common.rb
@@ -169,12 +169,8 @@ class HomeworkCommon < ApplicationRecord
 
   #删除时更新题库中的引用数
   def update_homework_bank_quotes
-    old_banks = self.homework_bank
-    unless old_banks.blank?
-      old_banks.each do |bank|
-        bank.update_attributes(quotes: (bank.quotes - 1) > 0 ? (bank.quotes - 1) : 0, homework_common_id: nil)
-      end
-    end
+    old_bank = self.homework_bank
+    old_bank.update_attributes(quotes: (old_bank.quotes - 1) > 0 ? (old_bank.quotes - 1) : 0, homework_common_id: nil)
   end
 
   # 查重是否有新结果