Promoting the urban-rural industrial integration at the county level is an important means to achieve Chinese-style modernization. Based on the data of 1672 counties in China from 2006 to 2021，we construct a theoretical analysis framework of the influence of urban-rural industrial integration on common prosperity and empirically test the influence of urban-rural industrial integration on common prosperity，its channels of action，and spatial spillover effects using the threshold model and spatial Durbin model.It is found that the impact of county urban-rural industrial integration on common prosperity has a positive U-shaped nonlinear characteristic，and this conclusion still holds after a series of robustness tests.Mechanism analyses show that the county urban-rural industrial integration can promote common prosperity through alleviating financing constraints and fostering introduction of enterprises，but this is only effective when county urban-rural industrial integration develops to a certain degree.In addition，the impact of county urban-rural industrial integration on common prosperity shows significant heterogeneity at both the regional and urban-rural industrial integration type levels.Further research finds a significant positive spatial spillover effect of county urban-rural industrial integration on common prosperity，and counties need to adopt appropriate urban-rural industrial integration models.Therefore，it is necessary to accelerate the county urban-rural industrial integration，optimize the financial support policies，strengthen the introduction and cultivation of enterprises，optimize the spatial distribution of urban and rural industries，and explore differentiated modes of urban and rural industrial integration.