This study selects panel data from 1 172 counties in China spanning from 2010 to 2023 as the research sample. It treats the national pilot zones for integrated urban—rural development as a quasi—natural experiment, delving deeply into the impact of these zones on common prosperity. The findings indicate that the national pilot zones for integrated urban—rural development can foster common prosperity. Mechanism analysis suggests that these zones promote common prosperity through bidirectional factor flow and the intelligent transformation of industries. Heterogeneity tests reveal that the promotional effect of the national pilot zones for integrated urban—rural development on common prosperity is more pronounced in the eastern and central regions, areas with low fiscal pressure, and regions with high entrepreneurial activity. Based on these findings, this paper proposes several policy recommendations: strengthening the fulcrum for business value—added and extending the agricultural industry chain, simultaneously promote the integrated construction of factor markets, solidifying the underlying technical support for digital and intelligent development, implementing targeted measures to address the challenges of insufficient momentum in urban—rural integration. These suggestions aim to provide a reference for promoting common prosperity.