Abstract: Through a systematic review of domestic and international research, this study identified key scientific issues within the Long-Term Athlete Development (LTAD) framework and established a theoretical chain encompassing "conceptual definition – theoretical support – research outlook – indigenous mode". The conceptual essence of the LTAD plan was elucidated, emphasizing the dual development of physical literacy and competitive ability, balancing holistic development with individual differences, integrating humanities and sports science disciplines, and prioritizing comprehensive planning alongside staged progression. Additionally, principles such as all-round development, stage-based development, individualized development, systematic development, and lifelong development were articulated. From the perspectives of sports philosophy, sports training theory, sports physiology, physical education, and sports management, the theoretical underpinnings supporting the long-term development of young athletes were analyzed. Furthermore, research directions were proposed, including uncovering the intrinsic meaning and talent growth patterns of athlete long-term development, conducting diversified evidence-based research on LTAD, and developing multifaceted planning guidelines for athlete development. The sustainable development of China's competitive sports should be guided by the long-term development needs of athletes, led by the concept of cultivating athletes with both moral and physical excellence, guaranteed by a training mechanism that combines selection and retirement, supported by a refined selection and training model, and guided by a training guideline that integrates selection, training, science, and service, to form a local mode for the long-term development planning of athletes.