Abstract: Abstarct: The increasingly significant phenomenon of rural population aging poses a severe challenge to China’ s food production and sustainable agricultural development. As an important transmission mechanism, the adjustment of planting structure can reveal the impact path of rural population aging on food production. Based on the panel data of provinces, autonomous regions and municipalities from 2008—2021, this study used a two-way fixed-effect model and an intermediary effect model to analyze the impact and mechanism of rural population aging on food production. The results show that: (1) the aging of rural population has no obvious negative impact on national grain production, and this result still holds true under a variety of robustness tests; (2) Cropping structure plays a complete intermediary effect in the process of promoting grain production due to the aging of rural population. (3) Heterogeneity analysis showed that rural population aging had a significant effect on grain production in the eastern, central and western regions, but not significantly in the northeast region. Based on this, the following countermeasures are proposed: first, to improve the precision of food policy targeting to ensure the sustainable development of food production; second, to develop social service organizations in the center of the aging workforce to improve food yields; third, to promote aging-friendly agricultural machinery to promote the quality of food production; and fourth, to cultivate high-quality agricultural practitioners in order to lay the support for the development of agricultural talents.