The problem of unbalanced regional development needs to be solved by strengthening the economic relations among regions. The industrial integration between regions will not only give play to the comparative advantages of each region to promote the overall economic development, but also promote the narrowing of regional economic differences through the integrated industrial system. Based on the input-output relationship of intermediate products, the evaluation index of inter-regional industrial convergence level is designed. Moreover, an inter-regional industrial convergence network with 30 provincial regions as regional units is constructed by using the data from Multi-Regional Input-Output Model for China in 2002, 2007 and 2012. The analysis shows that during the sample period, China’s inter-regional industrial integration network pattern is in dynamic evolution. While the overall level is significantly improved, there is also an imbalance in regional development. The level of industrial integration in some regions and other regions needs to be improved. The interregional industry convergence network in China has sector characteristics related to geographical location, and geographical factors have an important impact on the interregional industry convergence. The QAP regression method is used to analyze the impact of changes in the level of industrial integration between regions on the changes in economic development differences. The results show that the improvement of the level of industrial integration between regions is conducive to the reduction of regional economic differences. Therefore, it is necessary to actively deepen the reform of the socialist market economy system, promote the integrated development of inter-regional markets and industries, and weaken the restriction of geographical factors on regional industrial integration by accelerating the development of digital economy and infrastructure construction, so as to improve the level of regional industrial integration and optimize its network structure. while improving the development level of inter-regional industrial integration, it is also necessary to actively reduce the differences in capital accumulation and industrial structure between regions, so as to reduce the regional economic differences more effectively.