diff --git a/app/controllers/hacks_controller.rb b/app/controllers/hacks_controller.rb
index 4465d515d..c9e9097f8 100644
--- a/app/controllers/hacks_controller.rb
+++ b/app/controllers/hacks_controller.rb
@@ -48,7 +48,9 @@ class HacksController < ApplicationController
         hack.save!
         # 创建测试集与代码
         hack.hack_sets.create!(hack_sets_params)
-        hack.hack_codes.create!(hack_code_params.merge(modify_time: Time.now))
+        hack_codes = hack.hack_codes.new(hack_code_params)
+        hack_codes.modify_time = Time.now
+        hack_codes.save!
       end
       render_ok({identifier: hack.identifier})
     rescue Exception => e
@@ -67,10 +69,8 @@ class HacksController < ApplicationController
         # 新建
         @hack.hack_sets.create!(hack_sets_params)
         # 更新代码
-        if params[:hack_codes][:code] != @hack.code
-          hack_code_params = hack_code_params.merge(modify_time: Time.now)
-        end
-        @hack.hack_codes.create!(hack_code_params)
+        code_params = params[:hack_codes][:code] != @hack.code ? hack_code_params.merge(modify_time: Time.now) : hack_code_params
+        @hack.hack_codes.first.update_attributes!(code_params)
       end
       render_ok
     rescue Exception => e
diff --git a/db/migrate/20191209111347_add_index_for_hack_codes.rb b/db/migrate/20191209111347_add_index_for_hack_codes.rb
new file mode 100644
index 000000000..f1e655e21
--- /dev/null
+++ b/db/migrate/20191209111347_add_index_for_hack_codes.rb
@@ -0,0 +1,6 @@
+class AddIndexForHackCodes < ActiveRecord::Migration[5.2]
+  def change
+    HackCode.destroy_all
+    add_index :hack_codes, [:hack_id, :language], unique: true
+  end
+end