diff --git a/app/models/homework_bank.rb b/app/models/homework_bank.rb
index 7e13891d3..2fdfc613e 100644
--- a/app/models/homework_bank.rb
+++ b/app/models/homework_bank.rb
@@ -12,5 +12,5 @@ class HomeworkBank < ApplicationRecord
 
   validates :name, length: { maximum: 60, too_long: "不能超过60个字符" }
   validates :description, length: { maximum: 15000, too_long: "不能超过15000个字符" }
-  validates :reference_answer, length: { maximum: 15000, too_long: "不能超过15000个字符" }
+  validates :reference_answer, length: { maximum: 25000, too_long: "不能超过25000个字符" }
 end