Currently, the rapid expansion of the digital economy is essential for advancing the healthy development of the economy. Utilizing China’s provincial data for the years 2011–2020, this study examines the impact mechanism of the digital economy on carbon emissions by using a mediation model, a moderating model, and a threshold model. The results indicate that: (1) the digital economy significantly reduces carbon emissions, even with variations between different regions; (2) it also decreases carbon emissions through enhanced energy efficiency and innovations in technology. Enhancing industrial structure and optimizing the distribution of resources can bolster this reduction effect; (3) the degree of financial development and the reduction of carbon emissions are positively correlated and are subject to a dual threshold. Therefore, the government ought to seize opportunities for "new infrastructure" and "new digital technology" development to achieve "dual carbon".