Abstract: This paper analyzes the mechanism and path of digital economy promoting the economic development of underdeveloped areas in theory and practice. In terms of theoretical logic, digital economy has the effect of catching up, upgrading, poverty reduction and coordination in promoting economic development in underdeveloped areas. In terms of practical experiences, the “Guizhou Model” provides important experience and reference for the development of digital economy and economic growth in underdeveloped areas. Specifically, Guizhou experiences are to conduct the following five persistence: combining the national strategy and Guizhou's reality; cultivating new driving forces and improving economic transformation and upgrading; pushing forward the marketization of data elements and ensuring data security, promoting industrial innovation and cultivating market players, combining talent training with the integration of government, industry, academia and research. By creating a good institutional environment for the development of digital economy, using digital technology to break the bottleneck of economic development, popularizing new technologies and models from point to point, and sharing new opportunities for digital economic development by all subjects, underdeveloped areas will realize high-quality economic development with the help of digital economy.