Based on the perspective of regional collaboration, the three aspects of rural industrial integration behavior, integration effect and integration sustainability were selected, and a comprehensive evaluation index system for rural industrial integration was constructed, and the level of rural industrial integration between the country and the four southwestern provinces (cities) was comprehensively measured. The panel data from 2015 to 2020 in the country and four southwestern provinces (cities) were selected, and the method of combining entropy value method and TOPSIS was used to conduct empirical comparative analysis. It is found that the level of rural industrial integration in the four southwestern provinces (cities) is significantly lower than the national average, but the growth rate is obvious. The overall integration level of the four southwestern provinces (cities) is Chongqing, Sichuan, Guizhou and Yunnan from high to low, and the growth rate is Guizhou Province, Yunnan Province, Sichuan Province and Chongqing Municipality from high to low. Finally, the four southwestern provinces (municipalities) have strong complementarity in rural industrial integration, and put forward suggestions for the integrated development of rural industries in southwest China in combination with the construction background of the national unified market.