Abstract: In recent years, how to effectively reduce the burden of primary and secondary school teachers has been a hot topic concerned by all sides of society. Therefore, it is urgent to investigate the current situation of working hours of primary and secondary school teachers and its impact on their work load perception through a nationwide large-scale sample survey.Through a questionnaire survey of 48, 874 primary and secondary school teachers in China, on their working hours and the impact on their sense of work load, the following findings are found: First, the overall working hours of primary and secondary school teachers are long, and the time allocation structure is unreasonable. Second, there are significant differences in the working hours of teachers in different types of primary and secondary schools. Third, working hours, time spent on dispute handling and coordination, and subjective perception of working hours can significantly affect teachers' sense of work load. In order to further implement the work of reducing the burden of primary and secondary school teachers, it is suggested to clarify the work boundary and respect the professional autonomy of teachers; considering the differences of teacher groups, we should focus on special groups such as young female teachers and class teachers because of the "group" policy; we should also focus on managing workloads generated by non-instructional work.