Physical activities are reviewed a core pillar for enriching students’ campus life under China’s “Double Reduction” policy. But the psychological benefits of non-player students remain untested. This study examines whether the psychosocial benefits of campus sports extend to all student roles. We conducted a cross-sectional design. Data were collected from 514 students participating in a noon-recess sports league as players (19.07%), supporting staff (20.23%), and spectators (60.51%). The study utilized MGCFA, Welch’s ANOVA and Two One-Sided Tests (TOST) to confirm measurement invariance. There are two main findings: the scores of the Sense of Community in Sport (SCS) between students were statistically indifferent; the SCS independently accounted for 34.4% of the variance in school belongingness. These findings proved that whether students participate a competition, they can gain psychologically and increase belongingness from the environment. In promoting the psychosocial well-being and mental health of students, physical activities in campus might serve as a scalable, low-cost instrument; educators and policy makers should pay attention to building a more inclusive league environment for the majority.