In the dual context of the digital era and the aging society, the impact of the digital divide on the social participation of rural older adults requires urgent attention. Based on the data from the 2020 China Family Panel Studies, the article empirically investigates the impact of the digital divide on the social participation of rural older adults and its mechanism of action using regression analysis and mediation effect test. The study finds that the digital divide has a significant negative impact on the social participation of rural older adults, and unlikewith the use and knowledge divides has a negative impact on the social participation of rural older adults and, the access divide has a positive impact on the social participation of rural older adults. The digital divide mainly affects rural older adults' social participation through three channels: health status, cultural capital and social trust, and health status, cultural capital and social trust all positively affect rural older adults' social participation. Heterogeneity analyses revealed that the digital divide had a greater negative effect on the social participation of rural male older adults compared to women, but the opposite was true for political participation. The findings of the study can provide reference for enhancing the level of social participation of older adults in rural areas and actively responding to the crisis of population ageing.