Based on the panel data of 31 provinces in China from 2012 to 2020, this paper used Penman-Monteith Equation to estimate the content and net export of virtual water of four major food crops (paddy, wheat, corn, and soybean). Then the paper analyzes the impact of virtual water trade on regional food security by fixed-effects regression models.The results show that the virtual water content of food crops has obvious differences in species and space. Virtual water flows from north to south and increases year by year.And there is an obvious “inverted U-shaped” relationship between virtual water net transfer and regional food security, indicating that there should be a certain limit to the transfer of virtual water between regions. Sown area, per capita water resources, agricultural mechanization level and urbanization level all have significant effects on regional food security.In the end, this paper proposes several countermeasures to ensure regional food security including strengthening water conservancy construction, optimizing planting structure, developing water-saving agriculture and improving overall grain production capability.