This study aims to explore the effect of physical exercise on college students’ interpersonal communication skills and further analyze the mediating role of social physique anxiety between the two. As the social pressure and body image anxiety problems faced by modern college students are becoming increasingly prominent, it is of great significance to understand the mechanism of physical exercise in this context. Through research, it can not only help reveal the direct effect of physical exercise on college students’ interpersonal communication skills, but also deeply understand the indirect effect of social physique anxiety as a mediating factor, thereby providing a scientific basis for improving college students’ mental health and interpersonal communication skills. Methods: This study adopted a scale survey method, and selected the Physical Activity Rating Scale (PARS-3), Interpersonal Communication Skills Questionnaire Short Form (ICQ-15) and Social Physical Anxiety Scale (SPAC) as measurement tools. A total of 599 college students were randomly selected as samples from Sichuan Agricultural University, and data were collected through self-filled questionnaires. The PARS-3 scale is mainly used to assess the frequency and intensity of physical activities of college students, the ICQ- 15 questionnaire is used to measure the social skills, interaction ability and conflict handling level of individuals in interpersonal communication, and the SPAC scale is aimed at college students’ social physical anxiety, that is, the negative cognition and anxiety of individuals about their physical appearance in social situations. Data analysis used a combination of correlation analysis and regression analysis to evaluate the relationship between variables and test the mediating effect of social physical anxiety between physical exercise and interpersonal communication skills. Results: There was a significant negative correlation between physical activity and social physical anxiety (r=-0.305, p<0.01), a significant positive correlation between physical activity and interpersonal competence (r=0.315, p<0.01), and a significant negative correlation between social physical anxiety and interpersonal competence (r=-0.199, p<0.01); Physical exercise positively predicted interpersonal competence (β=0.196, p<0.001) and also negatively predicted social physical anxiety (β=-0.178, p<0.001), and social physical anxiety negatively predicted interpersonal competence (β=-0.117, p<0.01). Social physical anxiety mediates the relationship between college students’ physical exercise and interpersonal competence, and the proportion of its mediating effect is 11.20%. Conclusion: College students’ physical exercise can not only directly affect their interpersonal communication ability, but also indirectly affect their interpersonal communication ability through the mediating variable of social physical anxiety.