In an increasingly digital age, studying how the digital economy affects carbon emissions is important for China’s dual carbon goals. Based on the panel data of 30 provinces and regions in China from 2012 to 2020, the impact of the digital economy on carbon emissions in China and the mechanism of its effect are empirically analyzed. This study reveals that the digital economy has an inverted U-shaped impact on China’s carbon emissions. Initially, it promotes carbon emissions but later inhibits them. The carbon emission reduction effect is more significant after the digital economy reaches the inflection point of the inverted U-shape in the more economically developed regions. Energy structure and energy use efficiency are the two key factors through which the digital economy affects China’s carbon emissions. Among them, the digital economy shows an inverted U-shaped effect on energy structure, which is first positive and then negative, and a positive U-shaped effect on energy use efficiency, which is first negative and then positive. Based on the above findings, this paper suggests that: First, to achieve peak carbon and carbon neutrality, the digital economy needs to be strengthened and the foundations of the digital economy need to be consolidated. Second, the digital transformation of the energy sector should be accelerated, and digitalization should lead to the low-carbon energy transformation. Finally, in the process of developing the digital economy, attention should be paid to the rebound in energy consumption caused by a large number of basic digital facilities, and the low-carbon integration of the digital economy and traditional industries is of great significance in reducing carbon emissions.