diff --git a/app/controllers/exercise_answers_controller.rb b/app/controllers/exercise_answers_controller.rb
index e5d67b2d7..b1e23071b 100644
--- a/app/controllers/exercise_answers_controller.rb
+++ b/app/controllers/exercise_answers_controller.rb
@@ -14,19 +14,15 @@ class ExerciseAnswersController < ApplicationController
         else
           ea = @exercise_question.exercise_answers.search_answer_users("user_id",current_user.id)  #试卷的当前用户的答案
           if q_type == Exercise::SINGLE || q_type == Exercise::JUDGMENT  #选择题（单选）/判断题
-            ea_choice = ea.search_exercise_answer("exercise_choice_id",choice_id).first
-            answer_option = {
+            if ea.exists?
+              ea.first.update_attribute(:exercise_choice_id,choice_id )
+            else
+              answer_option = {
                 :user_id => current_user.id,
                 :exercise_question_id => @exercise_question.id,
                 :exercise_choice_id => choice_id,
                 :answer_text => ""
-            }
-            if ea_choice.present? #如果当前用户的答案存在，再次点击，即为删除
-              ea_choice.destroy
-            else
-              if @exercise_question.exercise_standard_answers.count <= 1  #单选题的时候
-                ea.first.destroy if ea.present?
-              end
+              }
               ex_a = ExerciseAnswer.new(answer_option)
               ex_a.save!
             end