<p>Based on the Conservation of Resources Theory and Person-Environment Fit Theory, this paper constructs a nonlinear model to explore how voluntary overqualification affects innovation performance and voice behavior. In this study, we analyzed matched data from 607 leader-employee pairs and found a curvilinear relationship between three types of voluntary overqualification and resilience, which is moderated by a humanistic-helpful culture. When the level of humanistic-helpful culture is high, employees with voluntary overqualification exhibit higher levels of resilience, and the U-shaped effect of voluntary overqualification on resilience becomes less pronounced. We hypothesized that idiosyncratic deal would moderate the U-shaped relationship between voluntary overqualification and resilience and enhance the impact of voluntary overqualification on resilience, but the data did not support our hypotheses. Resilience is positively correlated with innovation performance and voice behavior, and it plays a mediating role between voluntary overqualification and role performance. Our theoretical and empirical research contributes to advancing the field of overqualification research and provides guidance for managerial practice.</p>