diff --git a/db/migrate/20190722062800_modify_answer_for_challenges.rb b/db/migrate/20190722062800_modify_answer_for_challenges.rb
new file mode 100644
index 000000000..747564d68
--- /dev/null
+++ b/db/migrate/20190722062800_modify_answer_for_challenges.rb
@@ -0,0 +1,11 @@
+class ModifyAnswerForChallenges < ActiveRecord::Migration[5.2]
+  def change
+    challenges = Challenge.where("answer is not null or answer != ''")
+                     .includes(:challenge_answers).unscoped
+    challenges.find_each do |c|
+      next if c.challenge_answers.present?
+      puts("############challenge_id:##{c.id}")
+      ChallengeAnswer.create(name: "解题代码", contents: "#{c.answer}", level: 1, score: 100, challenge_id: c.id)
+    end
+  end
+end