Objective: To explore the bidirectional correlation between daily physical activity and different emotional states of university students with sports major, and to provide theoretical basis for promoting equality between physical and mental health of college students. Methods: The accelerometer and daily emotion scale were used to evaluate 219 physical education major college students recruited from Tianjin University of Sport. Correlation analysis, intra group correlation coefficient analysis and Harman single factor method were used to test the data, and Mplus 7.4 was used to analyze cross hysteria. Results: Physical activity was positively correlated with high arousal/low arousal positive emotion, and negatively correlated with low arousal/high arousal negative emotion ( r=0.94, 0.63, -0.28, -0.17, P <0.05). The cross lag model showed that physical activity on Thursday and Friday positively predicted high arousal positive emotion on Friday and Saturday, and high arousal positive emotion on Thursday and Friday positively predicted physical activity on Friday and Saturday( β =0.91, 0.20; 0.88, 0.39, P ＜0.05). Low arousal positive emotion on Thursday and Friday was a positive prediction of physical activity on Friday and Saturday, but only physical activity on Thursday positively predicted low arousal positive emotion on Friday( β=0.68, 0.35, 0.70, P ＜0.05). Low arousal negative emotion on Thursdays and Fridays negatively predicted physical activity on Friand and Saturdays( β=-0.37, -0.40, P ＜0.05). Conclusion There is a bidirectional correlation between daily physical activity and positive emotion, but a weak correlation with negative emotion. Attention should be paid to the emotional benefits of physical activity and the increasing physical activity by greater mood improvements.