The aim of college education is not only to teach students professional knowledge and skills but also to develop their self-regulated learning (SRL) ability, which has great significance for their lifelong development. This study aims to investigate the roles played by professional identity, intrinsic motivation, and sense of school belonging in improving SRL ability among college students. Mediation and moderated mediation analyses were employed to analyze a sample of 619 college students. The findings suggest that intrinsic motivation mediates the relationship between professional identity and SRL ability, and that sense of school belonging moderates not only a direct link between professional identity and SRL ability but also an indirect association between intrinsic motivation and SRL ability. Students with a high sense of school belonging show a stronger influence of professional identity and intrinsic motivation on improving SRL ability than those with a low sense of school belonging. Therefore, promoting professional identity and intrinsic motivation can be particularly beneficial for students with a strong sense of school belonging in improving SRL ability.