Based on the panel data of 30 provinces in China from 2013 to 2019, the theoretical framework and transmission mechanism of the impact of digital economy on carbon emission intensity are constructed from the production and consumption sides. The research finds that: Digital economy can significantly reduce carbon emission intensity and achieve carbon emission reduction effect, and the results are still significant after endogenous and robustness tests. In the sub dimensions of the digital economy, the development of information technology and the internet have significantly promoted carbon emission reduction, but the carbon emission reduction effect of the development of digital trading is not significant. There is heterogeneity in the impact of the digital economy on carbon emission reduction, and the carbon emission reduction effect of the digital economy is more significant in the central and eastern regions, high marketization levels, and high innovation and entrepreneurship levels. The mechanism analysis results indicate that the digital economy can achieve a reduction in carbon emission intensity by promoting the upgrading of industrial structure at the production end and the upgrading of consumption structure at the consumption end. This has important reference significance for achieving green and low-carbon development.