Abstract: Clarifying the mechanism through which rural population aging affects green agricultural development is of great significance for accelerating the green transformation of agriculture in China. Based on the panel data of 31 provinces (excluding Hong Kong, Macao and Taiwan) in China from 2003 to 2020, this study measured the level of agricultural green development in China, and empirically analyzed the influence mechanism of rural population aging on agricultural green development by using the fixed-effect model and the moderating effect model. The results show that, 1) The level of agricultural green development in China is consistently enhancing; however, the inter-provincial disparities are demonstrating an expanding tendency, and the dynamic adjustment of regional agricultural green development is conspicuous, featuring overall unbalanced development. 2) Rural population aging significantly inhibits agricultural green development, and its inhibitory effect is more prominent in low aging regions. And according to the fractal heterogeneity test, rural population aging inhibits resource conservation and economic effect, while it has a significant role in promoting environmental friendliness and has no effect on ecological conservation. In general, the negative effects of rural population aging outweigh the promotion effects, thus inhibiting agricultural green development. 3) The impact of rural population aging on agricultural green development exhibits a U-shaped nonlinear relationship, with an inflection point at 0.16. Since the majority of the sample is distributed to the left of this inflection point, the marginal impact is predominantly negative. 4) According to the development of China's agricultural socialized services, agricultural socialized services can notably enhance the level of agricultural green development. Meanwhile, it can exert a regulatory function in the process where rural population aging influences agricultural green development, that is, it can effectively mitigate the inhibitory impact of rural population aging on agricultural green development. Therefore, it is suggested that local policies should be adopted to promote agricultural green development and constantly narrow the development differences between different regions. Efforts should be made to enhance the human capital accumulation effect of elderly farmers, vigorously cultivate new professional farmers, support and encourage all types of new business entities to accelerate the supply of agricultural socialized services, actively guide elderly farmers to integrate into the social service system in an orderly manner, realize the organic connection between elderly farmers and modern agriculture, and promote agricultural green production.