Under the background of the knowledge economy, business managers have gradually realized that improving innovation performance requires breaking organizational boundaries to obtain knowledge, technology and other resources from the outside. As one of the important external subjects of new product development (NPD), customers actively participate in NPD activities become an effective way to acquire customer knowledge. However, there are still divergent studies on the effect of customer participation (CP) on NPD performance. In view of this, this research explores the relationship between customer participation, knowledge integration, absorptive capacity, and NPD performance, and this paper empirically studied the influence of CP on NPD performance through a large sample questionnaire survey, and focused on the analysis of the mediating role of knowledge integration and the moderating effect of absorptive capacity. The results show that CP has a significant positive effect on knowledge integration and NPD performance; knowledge integration has mediating effect between CP and NPD performance; Absorptive capacity positively moderates the relationship between CP and knowledge integration, but has no significant moderating effect on CP and NPD performance. From the perspective of knowledge management, this study links customer participation with NPD performance, and the research results not only have important theoretical implications for the in-depth study of customer participation, NPD performance, knowledge integration and absorptive capacity, but also have important practical significance to improve the success rate of NPD and promote high-quality development.