Background: Existing research has linked individuals' flow experience - a positive affective and cognitive state of deep immersion and engagement in daily activities - and their well-being, particularly among university students. A growing number of longitudinal studies have further contributed to this understanding. However, limited attention has been given to exploring the dynamic interplay between these two variables and their underlying mechanisms (i.e., the mediator) of psychological resilience, specifically among university students in the context of the COVID-19 pandemic. Aims: To address this research gap, the present study draws on self-determination, flow and broaden-and-build theories. It examines the temporal dynamics and relationships between flow experience and well-being, and the mediating role of psychological resilience among Chinese university students. Sample: The study adopts a three-wave longitudinal design with a sample of 474 university students in Southwest China. Methods: Participants' flow experience, well-being and psychological resilience were measured across three time waves. Results: The findings of this study reveal that flow experience predicts well-being across the three waves and that psychological resilience mediates this prediction. This empirical evidence emphasizes the significance of both flow experience and psychological resilience in contributing to the well-being of university students over time amid COVID-19. Conclusions: These findings enrich our understanding of the factors contributing to well-being in educational settings and provide highly relevant and timely insights for developing strategies to foster well-being among university students, especially in the transition into the post-pandemic era; findings also offer valuable insights not only for researchers but also for educators and policymakers.