<p>Achieving food security is an important sustainable development goal (SDG). This paper established a comprehensive assessment system for food security (FS) and agricultural digitization, and the impact of extreme weather on food security in China and the practical role of agricultural digitalization is analyzed. The results demonstrated that China’s FS continues to increase from 2004 to 2021. However, for every 1% increase in the extreme weather frequency, China’s grain unit output decreases by 1.3%, the total grain yield decreases by 0.005 units, and FS decreases by 0.004 units. Among extreme weather occurrences, extreme rainfall most notably adversely affects FS. Fortunately, agricultural digitization could significantly enhance FS. When agricultural digitization increases by 1 unit, FS increases by 0.129 units. By establishing an interaction term of agricultural digitization and extreme weather frequency, we determined that agricultural digitization could significantly help the food production sector overcome extreme weather, ensuring FS. Agricultural digitization fulfills the greatest positive role in China’s major grain-producing areas, especially in the central region. In Western China and nonmajor grain-producing areas, the effectiveness of agricultural digitization is not notable. Generally, this study is essential for helping countries worldwide assess agricultural digitization and FS levels, increase food production capacity, and alleviate hunger.</p>