diff --git a/app/models/course.rb b/app/models/course.rb
index f7db61995..14c17cf39 100644
--- a/app/models/course.rb
+++ b/app/models/course.rb
@@ -387,7 +387,7 @@ class Course < ApplicationRecord
   end
 
   def max_activity_time
-    course_acts.pluck(:updated_at).max
+    course_activities.pluck(:updated_at).max
   end
 
   # 课堂作业数
diff --git a/app/services/admins/school_daily_statistic_service.rb b/app/services/admins/school_daily_statistic_service.rb
index f81bc7bb6..fec289eae 100644
--- a/app/services/admins/school_daily_statistic_service.rb
+++ b/app/services/admins/school_daily_statistic_service.rb
@@ -45,7 +45,7 @@ class Admins::SchoolDailyStatisticService < ApplicationService
     courses = Course.where(is_delete: 0, school_id: ids).group('school_id')
     course_map = courses.count
     Rails.logger.info("####courses_daiao: #{courses.inspect}")
-    nearly_course_time_map = courses.joins(:course_acts).maximum('course_activities.updated_at')
+    nearly_course_time_map = courses.joins(:course_activities).maximum('course_activities.updated_at')
     active_course_map = courses.where(is_end: false).count
 
     shixun_map = Shixun.joins(user: :user_extension).where(user_extensions: { identity: :teacher, school_id: ids })