Abstract: After-school service refers to an educational activity that is carried out after students complete their compulsory education at school. With schools as the main channel and social educational resources as a supplement, after-school service can relieve parents' anxiety and meet students' diversified needs at the compulsory education stage. Whether sports, as an important part of after-school service, plays an effective role as expected is yet to be tested. Using the methods of questionnaire and mathematical statistic, this paper analyzes the current situation and problems of after-school sports service. The study shows that after-school sports service is relatively stable in terms of both time and frequency, and has a significant effect on the reduction of students' stress. But the differences in both learning stage and region are large, and the connection between grades is not steady. The reasons for the differences and limitations on student participation include the ambiguity of policy regulation, the lagging policy updates, the limitations of subjective and objective factors, the utility of educational environment and the incompleteness of supervision mechanism. In view of the present situation and problems of after-school sports service, the authors propose some optimization measures including strengthening publicity, tapping students' needs, supplementing teachers, upgrading the system, and strengthening supervision and incentives.

Key words: "double reduction" policy, after-school sports service, school sports, extracurricular sports activity