Abstract: The Law of the People’s Republic of China on Sports (the sports law), revised in 2022, serves as the fundamental legal guarantee for advancing the rule of law in China’s school physical education system. A thorough understanding of the provisions on school physical education within the sports law, coupled with enhanced efforts to promote legal awareness and enforce compliance, is crucial for driving the high-quality development of school physical education in China. This study explores the connotation and denotation of school physical education from the perspective of legal entities, and elucidates the implications of high-quality development in school physical education across macro, meso, and micro levels. Grounded in the Law on sports law’s stipulations on developmental objectives, guiding principles, and institutional frameworks for school physical education, and key elements of physical education instruction—and in view of existing challenges in China’s school physical education practices—the analysis delves into the legal safeguards provided by the sports law to ensure high-quality development of school physical education. Recommendations are proposed, including intensifying legal education on school physical education provisions, accelerating the formulation of supporting legislation, and strengthening supervision and guidance mechanisms to fully implement the provisions of the sports law on youth and school physical education.