Due to the fact that the study of the impact of digital economy, one of the important driving forces for high-quality economic development in China, on carbon emission intensity is of great significance for achieving high-quality economic development in China, empirical tests have been made of the impact of China’s digital economy on carbon emission intensity by using the panel regression model and the intermediary effect model with the panel data samples of 30 provinces and cities (excluding Xizang, Hong Kong, Macao and Taiwan) from 2013 to 2020. The results indicate that digital economy can directly suppress the increase in carbon emission intensity. There is a significant heterogeneity in the inhibitory effect of digital economy on carbon emission intensity among the three major regions of China, with the strongest in the eastern region, to be followed by the western region, and the weakest in the central region. Digital economy exerts an inhibitory effect on carbon emission intensity mediated by the upgrading of industrial structure, with no inhibitory effect by the rationalization of industrial structures to be found. Based on this, it is advisable to seek a further development of digital economy, a promotion of digital emission reduction, and an enhancement of the mechanism for upgrading the industrial structure.