After-school sports service is an extension of school sports. As a professional force, it is of great value for sports training institutions to participate in after-school sports service, which can effectively solve the problems such as the lack of teachers in schools leading to the poor development of after-school sports service. Effective supervision of sports training institutions can promote the high-quality development of after-school sports service. By using the method of literature and logical analysis, the following difficulties still exist in the current supervision of sports training institutions’ participation in after-school sports services: (1) The policy system is not perfect, the guidance is insufficient, and the government’s vague attention to the supervision of sports training institutions leads to the lack of basis for supervision; (2) The regulatory bodies are not clear, the division of responsibilities is not clear, and the regulatory pattern of multi-subject cooperation and co-governance has not been formed; (3) The quality evaluation system is not perfect, there are quantitative investigation over process investigation, result evaluation over process evaluation, resulting in difficult to guarantee the quality of service provided by training institutions. In view of the problems existing in the participation of sports training institutions in the supervision of after-school sports services, the following promotion paths are proposed: (1) Accelerate the improvement of the top-level design of sports training institutions in the supervision of after-school sports services, clarify the selection mechanism and supervision measures for entering the campus, and set up a “black and white list” of sports training institutions; Establish an accountability system to ensure the quality of after-school sports services from a macro level; (2) The government coordinates multi-department joint supervision, clarifies the regulatory responsibilities of each subject, and forms a new pattern of multi-subject cooperation and co-governance; (3) Further refine the specific content of supervision and form targeted supervision measures; (4) Innovate regulatory means, and use a series of digital technologies such as the Internet and artificial intelligence to build an “Internet + regulation” intelligent regulatory platform.