In the era of the digital economy，the development of e-commerce has emerged as a new engine driving China’s economic growth.Based on panel data from 1672 county-level regions in China spanning 2006 to 2021，this study empirically examines the impact of e-commerce development on county-level common prosperity，along with its underlying mechanisms.The findings reveal that county-level common prosperity in China has steadily improved，exhibiting a spatially decreasing pattern from the eastern to central，western and northeastern regions.Among the dimensions of common prosperity， spiritual well-being and coordinated development remain the primary constraints at the county level.E-commerce development significantly enhance county-level common prosperity.Mechanism analysis demonstrates that this effect is primarily achieved through three channels：promoting rural industrial integration，increasing non-agricultural employment opportunities，and facilitating industrial structure upgrading.Furthermore，the impact of e-commerce development on county-level common prosperity is more pronounced in counties located in central and western regions，as well as in counties with low levels of economic development and urbanization.