OBJECTIVE: This study investigates the association between physical exercise and emotion regulation abilities among college students, introducing self-efficacy as a mediating variable to analyze the pathway mechanism through which physical exercise affects emotion regulation abilities. METHODS: A cross-sectional study design was employed, utilizing a stratified random sampling method to survey three colleges in Jiangsu Province, China. Physical Activity Rating Scale, Physical Activity Self-efficacy Scale, and Emotional Intelligence Scale were used to measure the college student population. Regression analysis and mediation tests assessed whether self-efficacy mediates the relationship between physical exercise and college students' emotion regulation abilities. A total of 5,430 valid questionnaires were collected. RESULTS: The distribution of college students' physical activities was 77.0% for low, 13.1% for medium, and 9.3% for high levels. Physical activities were significantly and positively correlated with self-efficacy and emotional management abilities (r = 0.298,0.105;P<0.01), and self-efficacy was significantly and positively correlated with emotional management abilities (r = 0.322, P<0.01). Situational motivation and subjective support under self-efficacy were 0.08 and 0.255, respectively, and the adjusted R2 was 0.107. Self-efficacy played a fully mediating role between physical activities and emotional management abilities, with a total effect value of 0.032. The values of the direct and indirect effects were 0.003 and 0.029, accounting for 8.95% and 90.74% of the total effect, respectively. CONCLUSION: The physical exercise behavior of college students is primarily characterized by low intensity. Physical exercise among college students can positively predict their ability to regulate emotions. Self-efficacy fully mediates the relationship between physical exercise and emotion regulation ability among college students. College students can indirectly influence their ability to regulate emotions through physical exercise and self-efficacy.