Background: To explore the association between the self-reported health status, depressive tendency, psychological capital, and self-acceptance of college students in China during the COVID-19 pandemic. Methods: Using the online survey platform “questionnaire star”, a two-phase cross-sectional study was conducted on a total number of 1438 undergraduates with informed consents. The questionnaires of Self-Rated Health Measurement Scale (SRHMS), the Center for Epidemiological Studies-Depression Scale (CES-D), Psychological Capital Questionnaire (PCQ-24), and self-acceptance questionnaire were administered to each participant. Results: Male college students had significantly higher depressive tendency scores than female (17.59 vs. 15.82) (p < 0.01). College students having no siblings had significantly higher psychological capital scores than those having siblings (108.63 vs. 105.60) (p < 0.05). Exercise had significantly positive associations with self-rated health, psychological capital, and self-acceptance scores, while online time per day had significantly negative associations. Multivariate analysis showed that the interaction between depressive tendency, psychological capital, and self-acceptance was statistically significant (β = 0.004, p = 0.013 for phase 1 and β = 0.002, p = 0.025 for phase 2) in health status with depressive tendency ranking the top (β = −0.54 for phase 1 and −0.41 for phase 2, p < 0.001). Mediation analysis showed that psychological capital and self-acceptance modified the association of depressive tendency with health status. Conclusion: Physical exercise is beneficial to both physical and psychological health. Depressive tendency is the main risk factor that associates with self-rated health. Regardless of depressive tendency level, high psychological capital and self-acceptance could improve college students’ health.