The digital economy provides a new driving force for promoting common prosperity. Based on China's from 2013 to 2021 provincial panel data, the fixed effect and threshold effect models are constructed to explore the impact of digital economy on common prosperity. It is found that digital economy can significantly promote the realization of common prosperity, and the impact of digital economy on common prosperity exists a single threshold effect with agricultural mechanization as the threshold variable. Further study found that the promotion effect of digital economy on common prosperity is more effective in the eastern region, but not obvious in the central and western regions.