Abstract: From the perspective of public goods, this paper analyzes the structure, mechanism and social precondition of the unified market, explaining the theoretical logic and practical approach of unified market. Market mechanism does not exist naturally. Its formation requires the integration of institutional rules, its development needs to overcome huge social costs, and its operation has significant positive externality. The unified market is a kind of institutional public goods, which aims to realize its positive externality through the construction of positive efficiency-equity feedback mechanism. Therefore, we need to give full play to the fundamental role of government as the market builder, realize the potential of localization and internalization under the principle of systematic governance, and promote the coordinated development of economy and society. The unified market is helpful for promoting the transformation of China's market from big to strong, reflecting the essential requirement of establishing a new development paradigm in China.