Abstract: Based on the panel data of 41 prefecture-level cities in the Yangtze River Delta region from 2000 to 2022, this paper empirically analyzed the impact of digital economy on food security by using a two-way fixed-effect model. The results showed that, the development of digital economy could promote food security. This conclusion was still valid by the robustness test. Further heterogeneity analysis revealed significant differences between different city types and regions: in small and medium-sized cities, major grain-producing areas and major grain-selling areas, the digital economy significantly promoted the improvement of food security capabilities, while in large and above cities, the promotion effect was not obvious. Accordingly, this paper put forward corresponding policy recommendations to promote the full leverage of the digital economy in strengthening food security capacity and ensure national food security.