This study constructs an evolutionary game model of labor force， and between urban sector and rural sector， to explore the internal mechanism of labor mobility's impact on urban?rural integrated development. Based on the panel data from 31 Chinese provinces and municipalities from 2002 to 2020， it examines the characteristics of labor mobility and urban?rural development evolution， and empirically analyzes the effects and spatio?temporal heterogeneity of labor mobility on its development. The research finds that both the level of urban?rural integration and labor mobility has steadily increased， but regional disparities persist in both； that at national level， labor mobility significantly promotes the integrated development； that in temporal dimension， the marginal impact of labor mobility on the development has gradually decreased； and that in spatial dimension， its impact on the development is more prominent in the eastern region. Therefore， enhancing inter?regional labor mobility and focusing on resolving the regional mismatch of labor factors are key measures to improve the urban?rural integrated development.