Abstract: With the development of digital technologies such as the Internet and digital industries such as e-commerce, the digital economy has become a new force in China's economic transformation and upgrading, which has brought forth a new perspective for environmental governance, energy conservation, and emission reduction. Based on the data of 30 provinces in China from 2004 to 2019, this paper constructs the digital economy index from the two dimensions of digital industrialization and industrial digitization, and discusses the impact and transmission mechanism of digital economy on China's energy consumption intensity and carbon emission intensity. The results show that digital economy present a typical inverted U-shaped relationship with energy intensity and carbon intensity respectively. In other words, when the digital economy reaches a certain threshold, the double dividend of energy saving and emission reduction can be achieved, and this effect also exists in high-carbon emission areas, low-carbon emission areas and eastern and central regions. In addition, the two different dimensions of the development level of digital economy also show some differences. The dividend effect of energy conservation and emission reduction of digital industrialization should be realized before industrial digitization. Further, the development of digital economy affects energy consumption and carbon emissions through technological innovation, human capital accumulation, labor productivity, and financial development.

Key words: digital economy, energy consumption, carbon emissions, "inverted U" curve