Reducing carbon emissions is imperative for achieving sustainable development. Given China's rapid growth in its digital economy, it is necessary to explore the impact of digital economy on emissions intensity. This study employs China’s provincial panel data and uses the fixed effect model to examine this impact. The results reveal that digital economy can drop carbon emissions intensity, and the finding remains robust after conducting various endogeneity treatments and sensitivity analyses. This study also explores the mechanisms underlying this effect and finds that the expansion of the digital economy reduces carbon emissions intensity by enhancing green innovation capacity and promoting economic agglomeration. Additionally, we consider electricity consumption of digital economy, and the analysis reveals regional heterogeneity, with the emissions intensity reduction effect being significantly stronger in regions with green power generation compared to non-green power generation regions.