This study aims to explore the impact of digital literacy on cognitive function in rural empty-nest elderly in China and its underlying mechanisms. Using data from the 2020 China Health and Retirement Longitudinal Study (CHARLS), 2,325 eligible rural empty-nest elderly aged 60 and above were selected as the sample. Information on their digital literacy, social participation, depressive symptoms, cognitive function, education level, and related demographic data was collected. Correlation analysis was used to examine the relationships between variables, and the Process macro program was employed to test the chain mediation effect of social participation and depression, as well as the moderating role of education in the relationship between digital literacy and social participation.Research indicated that digital literacy can indirectly improve cognitive function in rural empty-nest elderly by enhancing social participation and alleviating depressive symptoms, and education strengthens this mechanism. This suggests that in efforts to improve digital literacy among rural empty-nest elderly, attention should be paid to educational differences, and more tailored digital support strategies should be designed for different education groups to promote social participation, improve depressive symptoms, and delay cognitive decline.