Exploring the impact of a new round of mixed-ownership reform on enterprise development has far-reaching implications for the future development of mixed-ownership reform and the improvement of internal and external corporate governance of the enterprise. This study makes a comprehensive analysis of the relationship between mixed-ownership reform and innovation performance using a combination of empirical testing and theoretical analysis. In terms of theoretical analysis, this study summarizes research on mixed-ownership reform and innovation performance, while also integrating the theoretical basis of the development and institutional background of China’s current mixed-ownership reform, and investigating the impact of mixed-ownership reform on innovation performance. A-share list of manufacturing companies from 2015 to 2018 is selected as the research object, and K-nearest neighbor matching, multiple regression model, and propensity score matching are used to test the effect of mixed-ownership reform on innovation performance. By comparing the changes in the innovation performance level of state-owned enterprises (SOEs) before and after the mixed-ownership reform, this study proposes that the SOEs will not only enhance the competitiveness among manufacturing companies but also will have a positive impact on the high-quality development of the entire society and industrial transformation and upgrading.