This chapter utilizes data from private enterprises listed on the Shanghai and Shenzhen stock markets from 2013 to 2019 to investigate the impact and mechanisms of reverse mixed ownership reform on the "greenwashing" behavior of private enterprises, approaching the study from the perspective of ownership structure. The research reveals that the introduction of state-owned shareholders through reverse mixed ownership reform can effectively inhibit the intensifying "greenwashing" issue among private enterprises through three channels: enhancing the enterprise"s financing capabilities, improving the short-sighted behavior of management, and increasing the enterprise"s sense of environmental responsibility. Differential analysis of the governance effect of state-owned equity finds that, compared to expressive manipulation, state-owned equity has a more significant inhibitory effect on selective disclosure. By introducing a quadratic term of reverse mixed ownership reform, it is verified that there is an optimal participation ratio for state-owned equity. Heterogeneity analysis, considering the nature of the industry, the degree of enterprise information disclosure, and corporate reputation, unveils the green governance effect of reverse mixed ownership reform under different circumstances. Based on these findings, this chapter proposes relevant suggestions from three aspects: to further promote the process of reverse mixed ownership reform in private enterprises, to perfect laws and regulations regarding information disclosure, and to strengthen corporate team building.