Building on knowledge management and innovation capability theories, this paper aims to reveal the mechanisms of collaborative innovation processes by investigating the complex relationships among critical factors influencing firm's innovation performance in supply chain networks. Using hierarchical Multiple Regression (MR) and Moderated Multiple Regression (MMR) methods, results from a survey of 236 firms in China indicated that there are significant positive relationships between collaborative innovation activities, knowledge sharing, collaborative innovation capability, and firm's innovation performance. Moreover, it is expected that knowledge sharing plays a partial mediating role in the relationships between collaborative innovation activities and firm's innovation performance. Collaborative innovation capability exhibited a moderating effect on collaborative innovation activities - innovation performance relationship. These results contribute to collaborative innovation process management by offering a nuanced conceptualization of the collaborative innovation - performance relationship in supply chain networks.