Common prosperity is the essential requirement of socialism and an important feature of the Chinese path to modernization. Promoting common prosperity is inseparable from building a high-level socialist market economic system. State-owned enterprises are the foundation of the socialist market economy with Chinese characteristics. To promote common prosperity, it is necessary to steadily promote the reform of mixed ownership of state-owned enterprises, and enhance the strength, quality, and size of SOEs. The current round of mixed ownership reform of state-owned enterprises has promoted the integrated development of the state-owned economy and the market economy and achieved remarkable results in improving the operation efficiency of state-owned enterprises and promoting economic growth. However, different reform paths have also exposed new problems, such as insufficient protection of employees’ rights and interests, improper handling of the relationship between efficiency and fairness, and unreasonable performance compensation systems, which have affected the realization of common prosperity. This paper analyzes the influence of the existing problems of mixed ownership reform on common prosperity from the aspects of overall listing, the introduction of strategic investors, employee stock ownership plan, state-owned enterprise debt and so on. It also puts forward policy suggestions from the aspects of giving full play to the leading role of state-owned enterprises in industrial development, deepening the driving effect of scientific and technological innovation in the state-owned economy, accurately identifying the functional positioning of state-owned enterprises, improving corporate governance structure, optimizing business environment, and promoting the modernization of distribution system. The reform of mixed ownership of state-owned enterprises should start with model innovation to promote the high-quality development of state-owned enterprises. While maintaining the resilience and sustainability of economic growth, we should focus on improving people’s livelihood in the medium and long term, and promote the early realization of China’s goal of common prosperity.