Abstract: Digital economy reshapes the traditional economic structure by changing production mode, management mode and consumption mode, which plays an important role in realizing sustainable development. Taking 108 cities along the Yangtze River Economic Belt from 2011 to 2021 as the research object, this paper analyzes the influence of digital economy development on urban energy efficiency by using entropy method, super-efficiency SBM model and panel regression model. The results show that the development level of digital economy and urban energy efficiency of cities along the Yangtze River Economic Belt have improved significantly during the study period. The spatial evolution characteristics of digital economy development level gradually expands from single-center to multi-center distribution pattern, and the energy efficiency changes in an inverted "U" shape. The development of digital economy has a significant positive impact on energy efficiency, as do industrial structure, human capital stock and scientific and technological level.