Abstract: Promoting common prosperity and realizing the modernization of social governance are the purpose of the Communist Party of China and the essence of socialism, so Chinese society needs to build a social policy system centered on common prosperity. From the perspective of common prosperity, this paper finds that at present, China's social governance pays more attention to fairness and justice, coordination and balance, as well as mutual participation, and the function of China's social policies has shifted from focusing on "basic needs" "supplementary vacancies" and "providing welfare" to focusing on "shared rights" "inclusive well-being" and "providing service". During the "14th Five-Year Plan" period, optimizing the social policy system should place great emphasis on inclusive programs that help improve livelihood and provide social welfare assistance, optimize the design of social policy according to the changes in social structure, and deepen the reform of distribution system to promote fairness and justice.