Based on the background of the new development pattern of "dual circulation", firstly, this article uses the backward inference method from the perspective of the integration of internal and external, and the combination of both sides of supply and demand to construct a theoretical and logical framework for the digital economy to drive consumption growth, that is, "the new development pattern of dual circulation←domestic circulation as the main body←expansion of domestic demand←supply and demand matching←industrial structural upgrading and innovation←digital economy". Secondly, this paper selects data from 286 prefecture-level cities in China, uses cluster analysis to describe the level of digital economy development in each city and conducts a comparative analysis. It is found that there are obvious differences in the digital economy growth rate of cities at different levels. The digital economy index level of the first-tier cities of the digital economy is much higher than that of the other four-tier cities, but the growth rate of the fifth-tier cities of the digital economy far exceeds that of the first-tier cities. It can be seen from the fitting situation of the digital economy and consumption that the digital economy and consumption growth are positively correlated; the digital economy and industrial structure upgrading, industrial structure upgrading and consumption growth have a certain positive relationship, but the reality is that cities with a relatively high industrial structure optimization index have not clearly shown a corresponding good consumption momentum. The paper further establishes a moderated mediation effect model to empirically test the influence mechanism of the digital economy on consumption growth. The results show that from the full sample level, the overall effect of the digital economy on consumption growth is significantly positive, indicating that the digital economy can play a certain role in promoting consumption and stimulating domestic demand. In addition, the mediating effect of industrial structure upgrading is significantly positive, indicating that the digital economy can promote consumption growth by promoting industrial structure upgrading, but this mediating effect has certain regional differences. From a regional perspective, the intermediary effect of industrial structure upgrading is not significant in the eastern region, and significant in the central and western regions. The main reason for the insignificant intermediary effect of the eastern region is that the path of industrial structure upgrading affecting consumption growth is blocked. The main reason for this phenomenon is that the industrial structure upgrading in the eastern region has reached a certain height, but there are still some structural mismatch problems in promoting consumption upgrading. Further, this research uses science and technology expenditures as a moderating variable to test the eastern region. The test results find that science and technology expenditures have a positive regulatory effect on the digital economy's impact on consumption growth, and when the science and technology expenditures are higher, the intermediary effect of the industrial structure upgrading between digital economy and consumption will be significantly enhanced, that is, there will be a regulated intermediary effect. This shows that increasing the expenditure on science and technology will help correct the blocked path in the eastern region, and make the intermediate path for the entire industrial structure upgrading unblocked. Finally, targeted countermeasures and suggestions are putting forward. From the perspective of industrial structure upgrading, the article conducts theoretical and empirical analysis of the internal mechanism of the digital economy influencing consumption growth, and makes reasonable adjustments to the path of obstruction. This provides an effective policy reference for the government to accelerate the construction of a new "dual circulation" development pattern.