Based on data from the 2020 China Rural Revitalization Comprehensive Survey, this study uses a sample of 2508 farm households from 10 provinces to empirically examine the effect of farmers’ e-commerce participation on common prosperity and its underlying mechanisms. The benchmark regression results indicate that farmers’ e-commerce participation significantly promotes common prosperity. The findings remain robust after a series of robustness checks, including propensity score matching (PSM), Tobit estimation, instrumental variable approaches, and alternative measures of the core explanatory variable. Heterogeneity analysis indicates that farmers’ engagement in e-commerce business has a significantly positive effect on common prosperity in the eastern, central, and western regions, with the largest estimated effect observed in the central region. Moreover, farmers’ engagement in e-commerce business significantly enhances common prosperity across groups with different income levels and average household educational attainment, with larger estimated effects among low-income households and those with lower average education levels, indicating greater benefits for relatively disadvantaged groups. Mechanism analysis results indicate that farmers’ participation in e-commerce operations mainly promotes common prosperity through two pathways: improving rural credit accessibility and enhancing information acquisition capabilities.