Based on the social exchange theory, the current constructs a model of transformational leadership influencing employees' perceived overqualification through perceived organizational support. Using the questionnaire survey method, a total of 375 valid questionnaires were collected from a large manufacturing enterprise in China. The results show that: (1) Transformational leadership has a significant negative impact on employees' perceived overqualification; (2) Transformational leadership has a positive impact on employees' perceived organizational support, and perceived organizational support has a negative impact on employees' perceived overqualification; (3) Perceived organizational support plays a mediating role between transformational leadership and perceived overqualification. The study conclusion has a certain reference value both in theory and management practice. Finally, the limitations of the research are pointed out and future research prospects are made.