diff --git a/app/controllers/student_work_controller.rb b/app/controllers/student_work_controller.rb
index 909c68715..d4646f7d5 100644
--- a/app/controllers/student_work_controller.rb
+++ b/app/controllers/student_work_controller.rb
@@ -792,7 +792,7 @@ class StudentWorkController < ApplicationController
     if homework_detail_manual.ta_proportion.to_s != params[:ta_proportion].to_s || @homework.teacher_priority.to_s != teacher_priority.to_s || (homework_detail_programing && homework_detail_programing.ta_proportion.to_s != params[:sy_proportion].to_s)
       homework_detail_manual.ta_proportion = params[:ta_proportion]
       homework_detail_programing.ta_proportion = params[:sy_proportion] if homework_detail_programing
-      @homework.teacher_priority = teacher_priority
+      @homework.update_column('teacher_priority', teacher_priority)
 
       homework_detail_manual.save if homework_detail_manual
       homework_detail_programing.save if homework_detail_programing
@@ -1175,8 +1175,12 @@ class StudentWorkController < ApplicationController
               final_score = final_ta_score + final_s_score
               student_work.final_score = format("%.2f",final_score.to_f)
             end
-            score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty if student_work.final_score
-            student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+            if student_work.final_score
+              score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty
+              student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+            else
+              student_work.work_score = nil
+            end
           end
         else  #不考虑教师评分
           if student_work.teaching_asistant_score.nil?
@@ -1190,8 +1194,12 @@ class StudentWorkController < ApplicationController
             final_score = final_ta_score + final_s_score
             student_work.final_score = format("%.2f",final_score.to_f)
           end
-          score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty if student_work.final_score
-          student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+          if student_work.final_score
+            score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty
+            student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+          else
+            student_work.work_score = nil
+          end
         end
       elsif homework.homework_type == 2 && homework.homework_detail_programing #编程作业-----设定：系统评分必定不为空
         if homework.teacher_priority == 1 #教师优先
@@ -1226,8 +1234,12 @@ class StudentWorkController < ApplicationController
               final_score = final_sy_score + final_ts_score + final_st_score
               student_work.final_score = format("%.2f",final_score.to_f)
             end
-            score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty if student_work.final_score
-            student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+            if student_work.final_score
+              score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty
+              student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+            else
+              student_work.work_score = nil
+            end
           end
         else  #不考虑教师评分
           if student_work.teaching_asistant_score.nil? #教辅未评分
@@ -1257,8 +1269,12 @@ class StudentWorkController < ApplicationController
             final_score = final_sy_score + final_ts_score + final_st_score
             student_work.final_score = format("%.2f",final_score.to_f)
           end
-          score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty if student_work.final_score
-          student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+          if student_work.final_score
+            score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty
+            student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+          else
+            student_work.work_score = nil
+          end
         end
       end
     end
diff --git a/app/models/student_work.rb b/app/models/student_work.rb
index 40c66a632..989df40b0 100644
--- a/app/models/student_work.rb
+++ b/app/models/student_work.rb
@@ -63,11 +63,17 @@ class StudentWork < ActiveRecord::Base
               final_score = final_ta_score + final_s_score
               student_work.final_score = format("%.2f",final_score.to_f)
             end
-            score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty if student_work.final_score
-            student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+            if student_work.final_score
+              score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty
+              student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+            else
+              student_work.work_score = nil
+            end
           end
         else  #不考虑教师评分
-          if student_work.teaching_asistant_score.nil?
+          if student_work.student_score.nil? && student_work.teaching_asistant_score.nil?
+            student_work.final_score = student_work.teacher_score
+          elsif student_work.teaching_asistant_score.nil?
             student_work.final_score = student_work.student_score
           elsif student_work.student_score.nil?
             student_work.final_score = student_work.teaching_asistant_score
@@ -78,8 +84,12 @@ class StudentWork < ActiveRecord::Base
             final_score = final_ta_score + final_s_score
             student_work.final_score = format("%.2f",final_score.to_f)
           end
-          score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty if student_work.final_score
-          student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+          if student_work.final_score
+            score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty
+            student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+          else
+            student_work.work_score = nil
+          end
         end
       elsif homework.homework_type == 2 && homework.homework_detail_programing #编程作业-----设定：系统评分必定不为空
         if homework.teacher_priority == 1 #教师优先
@@ -114,9 +124,13 @@ class StudentWork < ActiveRecord::Base
               final_score = final_sy_score + final_ts_score + final_st_score
               student_work.final_score = format("%.2f",final_score.to_f)
             end
-            score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty if student_work.final_score
-            student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
-          end
+            if student_work.final_score
+              score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty
+              student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+            else
+              student_work.work_score = nil
+            end
+            end
         else  #不考虑教师评分
           if student_work.teaching_asistant_score.nil? #教辅未评分
             if student_work.student_score.nil?
@@ -145,8 +159,12 @@ class StudentWork < ActiveRecord::Base
             final_score = final_sy_score + final_ts_score + final_st_score
             student_work.final_score = format("%.2f",final_score.to_f)
           end
-          score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty if student_work.final_score
-          student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+          if student_work.final_score
+            score = student_work.final_score - student_work.absence_penalty - student_work.late_penalty
+            student_work.work_score = format("%.2f",(score < 0 ? 0 : score).to_f) if score
+          else
+            student_work.work_score = nil
+          end
         end
       end
     end