Abstract To consolidate existing evidence and clarify the association between physical activity (PA) and mental health among college students, through a systematic review of domestic and foreign literature, the study summarizes the dynamic bidirectional relationship between college students PA and mental health (including mood, depression, anxiety, sleep, and life satisfaction), and explores underlying mechanisms. The results indicate that PA could improve mood, alleviate depression and anxiety, promote better sleep, and improve life satisfaction, whereas mental health status can also have a reverse impact on PA motivation and behavioral patterns. In conclusion, a dynamic two way relationship exists between the two, and future research should further refine measurement, design, and methodology to provide a basis for promoting mental health in colleges.