Because the integrated development of rural industry promotes the application of the agricultural green production mode, it inevitably has an impact on the green development of agriculture. Analysing the influence of rural industry integration on agricultural green development is of great significance for realizing agricultural modernization and sustainable development. Based on panel data of 30 provinces in China during 2010-2021, the entropy weight TOPSIS method was used to estimate the agricultural green development level (AGD) and the rural industrial integration level (RII). The influence of agricultural industry integration (AII) on the level of agricultural green development (AGD) and its nonlinear characteristics were analysed by constructing a fixed model, intermediary effect model and threshold effect model. The results show the following. (1) A significant positive relationship exists between the RII and the AGD; that is, the development of rural industry integration can effectively promote the green development of agriculture. Regarding the three regions in China, the integration of rural industries in eastern China plays the most prominent role in the green development of agriculture. (2) Rural industrial integration has significant scale, capital and technology effects; that is, rural industrial integration mainly promotes AGD indirectly by promoting agricultural scale management and agricultural technological progress and improving rural human capital. (3) Rural industrial integration has a significant nonlinear marginal increasing effect on AGD. In the dynamic process of AGD changing from low to high, the effect of the marginal utility of rural industrial integration on AGD is gradually enhanced. Therefore, China should strengthen the deeply integrated development of rural industries, ensure the appropriate scale operation of agriculture and adjustments to the planting structure, accelerate agricultural technology innovation and rural human capital accumulation, and realize a win‒win situation for rural economic and ecological conservation.