Abstract: Among the various factors that drive high-quality economic development, the digital economy has become the largest new driving force. Based on a comprehensive analysis of the connotation of the digital economy, an evaluation system was constructed from the dimensions of development environment, digital industrialization, industrial digitization, and digital governance, and the entropy TOPSIS method was used to measure the 2016-2018 China Digital Economy Development Index. At the same time, based on the improved Feder two sector model, this paper discusses the theoretical mechanism of digital economy to promote high-quality economic development directly and through economic efficiency improvement and economic structure optimization, and makes an empirical test. The study found that，first, the scale of China's digital economy is expanding and the digital transformation is accelerating; second, the greater the possibility that high-quality economic development is constrained by low economic efficiency and unreasonable economic structure, the more significant the role of digital economy in promoting high-quality economic development. Accordingly, this paper proposes to promote the construction of new infrastructure, develop digital economy, promote the improvement of economic efficiency and the optimization of economic structure, promote the transformation of government governance mode, and then promote the high-quality development of China's economy.
