Based on 2008-2018 panel data of 30 provinces in China(Due to missing data, Tibet, Hong Kong, Macao and Taiwan are not included) to explore the technological innovation and upgrade of industrial structure to affect the path of economic development. This paper takes the upgrading of industrial structure as a mediating variable and refines it into the upgrading of industrial structure and the rationalization of industrial structure, discusses the transmission role of technological innovation in promoting economic development, and analyzes the regional heterogeneity by dividing China into the east, the middle and the west. The results show as follows: (1) Technological innovation and industrial structure upgrading can significantly promote regional economic development, and industrial structure upgrading plays a mediating variable role in the process of technological innovation to promote economic development.(2) The promotion effect of technological innovation on economic development in the eastern region is completely achieved through the upgrading of industrial structure, while the promotion effect of scientific and technological innovation on economic development in the western and central regions is partly achieved through the upgrading of industrial structure.(3) For mediation variables, the optimization of the industrial structure and the rationalization of industrial structure in the eastern region show a complete intermediate-effect in the process of technological innovation to promote regional economic development. The optimization of the industrial structure in the central region shows partial mediating effect, while the rationalization of industrial structure shows complete mediating effect, while the optimization of the industrial structure and rationalization of industrial structure in the western region both show partial mediating effect. (4) The opening up of the eastern region is an important factor affecting the economic development of the region. Fixed capital investment has a great influence on the economic development of central region, we should continue to increase fixed capital input. However, the economic development of the western region is still in a state of catch-up, and it is of Paramount importance to catch up with the economic development of the central and eastern regions and overcome the regional development imbalance.