How does the pilot policies of new urbanization improve uneven development?

China's current economic transformation is constrained by uneven development, which stems from traditional materialistic urbanization and results in a growing urban-rural divide and regional economic disparities. Based on the important judgment of the Chinese government relying on new urbanization to improve the uneven development, this article adopts a double difference method to analyze the policy outcomes of new urbanization pilot policies (NUPP). The findings indicate that:(1) NUPP could alleviate the uneven development within and between cities by promoting both urban-rural integration (URI) and regional synergy (SYN).(2) Rural human capital accumulation (RHCA) and industrial structure upgrading (ISU) are mediating conductance mechanisms for NUPP to affect URI and SYN, respectively.(3) the promotion effect of NUPP on URI and SYN is positively correlated with policy execution intensity and duration; (4) the dominant path of NUPP in alleviating uneven development has shifted from one-way promotion of URI to two-way promotion of URI and SYN; (5)the impact of spatial spillage of NUPP on URI is positive, with a spillover boundary of 180km, while that of SYN is negative, with a spillover boundary of 260km. This article reveals the governance logic of China's improvement of uneven development through NUPP, which is beneficial to the promotion and replication of the Chinese solution.