Promoting urban-rural integration through county-level platforms is of great significance for enhancing the functional connection and complementarity between counties， towns， and villages，optimizing the allocation of resources and factors，and increasing farmers’income. Based on the quasi-natural experiment of the “National Urban-Rural Integration Development Pilot Zone Reform”，this study explores the impact and mechanism of county-level urban-rural integration on farmers’income growth. Research has found that the county-level urban-rural integration contributes to a 1.5% increase in farmers’ income in pilot areas. This integration promotes income growth by facilitating labor mobility，encouraging large-scale crop management，and upgrading industrial structure. Meanwhile， the income growth effect of county-level urban-rural integration is more pronounced in the eastern region，areas with higher economic development levels， and regions with stronger fiscal capacity. Accordingly，the implementation of subsequent policies in the urban-rural integration development pilot zone should focus more on removing institutional barriers to labor mobility between urban and rural areas，promoting the integrated development of primary，secondary，and tertiary industries in rural areas，and establishing a sound urban-rural circulation system for agricultural products to stabilize farmers’ income growth.