diff --git a/app/controllers/shixuns_controller.rb b/app/controllers/shixuns_controller.rb
index b91ce9580..265398833 100644
--- a/app/controllers/shixuns_controller.rb
+++ b/app/controllers/shixuns_controller.rb
@@ -205,7 +205,7 @@ class ShixunsController < ApplicationController
 						new_challenge.save!
 						# 同步参考答案
 						challenge.challenge_answers.each do |answer|
-							new_answer = Challenge.new
+							new_answer = ChallengeAnswer.new
 							new_answer = answer.attributes.dup.except("id","challenge_id")
 							new_answer.challenge_id = new_challenge.id
 							new_answer.save!