Based on the panel data of cities in the Yangtze River Delta region from 2011 to 2021, Through the two-way fixed effect model, this paper explores the mechanisms, effects and heterogeneity of digital finance development in promoting the upgrading of industrial structure. The results show that digital finance can significantly promote the upgrading of industrial structure, among which innovation and entrepreneurship is an important transmission path, and technology and finance play a key role in the process. Heterogeneity analysis shows that in non-central cities and cities with high consumption level, the promotion effect of digital finance development on industrial structure upgrading is more obvious. Therefore, it is necessary to further strengthen the construction of digital financial infrastructure, build an innovation-driven entrepreneurial environment, promote, and optimize the consumption environment according to city conditions.