Mixed ownership reform is an important content and key breakthrough of state-owned enterprise reform, and also an important measure to support the development of private enterprises. However, how the mixed ownership reform affects the innovation of state-owned and private enterprises is still unclear. In addition, at the present stage, there are still some key problems in the mixed reform, such as "mixed but not changed", "mixed but not suitable", "lack of motivation", and so on. The main reform objectives of improving the operation and governance efficiency of state-owned enterprises have not yet been achieved. Therefore, in the key period of comprehensively deepening the reform, by systematically combing the existing research, we can clarify the impact mechanism and results of mixed ownership reform on enterprise innovation, and then point out the shortcomings and future direction of existing research, which will not only help to understand and guide the management practice of mixed ownership reform, but also help to enrich the relevant theories of mixed ownership reform and innovation research. In addition, combined with the analysis results of CiteSpace, vosviewer and other three measurement visualization tools, this paper constructs a research framework of mixed ownership reform with the main line of "influencing factors implementation process governance effect", and further reviews the research status and shortcomings of each part of the framework, in order to promote the further development of mixed ownership reform research.