diff --git a/app/helpers/exercises_helper.rb b/app/helpers/exercises_helper.rb
index 285dbb37e..9526acaf1 100644
--- a/app/helpers/exercises_helper.rb
+++ b/app/helpers/exercises_helper.rb
@@ -424,13 +424,13 @@ module ExercisesHelper
             end
             ex_shixun_answer_content = answers_content&.where(exercise_shixun_challenge_id: exercise_cha.id)
             if ex_shixun_answer_content.blank?  #把关卡的答案存入试卷的实训里
-              cha_path = challenge_path exercise_cha.challenge.path
-              game_challenge = game.game_codes.search_challenge_path(cha_path).first
+              cha_path = challenge_path exercise_cha.challenge&.path
+              game_challenge = game.game_codes.search_challenge_path(cha_path)&.first
               if game_challenge.present?
                 game_code = game_challenge
                 code = game_code.try(:new_code)
               else
-                code = git_fle_content(exercise_cha.shixun.repo_path,cha_path)
+                code = git_fle_content(exercise_cha.shixun&.repo_path,cha_path)
               end
               sx_option = {
                   :exercise_question_id => q.id,