As a driving force behind China’s modernization, the private sector contributes over 50% of tax revenue, 60% of GDP, 70% of technological innovation outcomes, 80% of urban employment, and 90% of the number of enterprises. Its vitality directly affects the prosperity and stability of the entire socio-economic system. However, the current development of the private economy is facing three major pressures: overall fluctuations and trend contraction, intensified horizontal competition and obstacles to vertical upgrading, and declining innovation quality and insufficient transformation momentum. Addressing the structural, institutional, and cyclical issues in the development of the private economy has become one of the most urgent problems to be resolved, and the key lies in creating a fair and just business environment conducive to the flow of factors of production and improving the efficiency of factor mobility services.

Against this backdrop, this paper utilizes the LandScan global population distribution high-resolution dataset to construct an indicator of urban multi-centered structure, employs private enterprise business registration data at the city-industry-year level from 2001 to 2022 to construct an indicator of private economy vitality, and combines labor, technology, and capital inter-city flow indicators derived from census, patent transfer, and inter-regional investment data to examine the impact of urban multi-centered spatial structure on private economy vitality and its underlying mechanisms. The study finds that a multi-centered spatial structure of cities is conducive to enhancing the vitality of the private economy, as evidenced by the fact that higher multi-centeredness and a greater number of centers increase both the increment and stock of private enterprises. This promotion effect exhibits heterogeneity across the core-periphery, inland-coastal areas, and intra- and inter-urban agglomeration dimensions. Mechanism testing indicates that a multi-centered spatial structure enhances the vitality of the private economy by attracting population inflows, technology transfers, and capital inflows. Further analysis reveals that the revitalizing effect of a multi-centered spatial structure on the private economy is stronger in cities with better market environments, superior credit environments, and more stable labor and employment environments. The study concludes that, at present, a multi-centered structure helps alleviate agglomeration inefficiencies and promote the development of the private economy.