<p>This longitudinal investigation examines the mediating and moderating processes that elucidate the association between social rejection and depressive symptoms in a cohort of university students. The study employed a two-wave design, with baseline data (T1) collected from 686 undergraduate students enrolled at a higher education institution in Henan Province, China. Of these participants, 304 successfully completed the subsequent assessment phase conducted 12 months later (T2). The theoretical framework posited a mediation model in which future orientation (T2) serves as a psychological mechanism transmitting the effects of social rejection (T1) on depressive symptoms (T2), with cognitive flexibility (T1) hypothesized to exert a conditional influence on this mediated relationship. The analytical results provided empirical support for the proposed model, indicating that future orientation significantly mediated the association between social rejection and depressive symptoms. Moreover, cognitive flexibility moderated the latter stage of this mediation, weakening the relationship between future orientation and depressive symptoms for individuals with higher cognitive flexibility. Contrary to expectations, the analysis revealed no significant moderating effect of cognitive flexibility on the direct association between social rejection and future orientation. These empirical findings highlight the selective protective function of cognitive flexibility, particularly in mitigating the psychological impact of future orientation on depressive outcomes. The results provide valuable empirical evidence for developing targeted intervention strategies, suggesting that therapeutic approaches focusing on the enhancement of both cognitive flexibility and future-oriented thinking may prove particularly beneficial in promoting psychological well-being among university populations.</p>