Abstract: The construction of national modern agricultural industrial parks, as an important initiative to promote agricultural modernization and rural revitalization, has been widely implemented across China. Based on county-level panel data from 2013 to 2023, this study employs a quasi-natural experiment design and a difference-in-differences (DID) model to systematically evaluate the impact of National Modern Agricultural Industrial Park construction on farmers' income. The results show that, first, the construction of these parks significantly increases farmers' income, with more pronounced effects on rural residents' disposable income and operating income. Second, the parks promote farmers’ income growth through two main channels. On the one hand, they advance agricultural industrial development by increasing agricultural output, expanding agricultural employment, fostering the establishment of agricultural enterprises, and enhancing industrial agglomeration. On the other hand, they stimulate non-agricultural industrial development by increasing the value added of secondary and tertiary industries and raising the proportion of non-agricultural employment. Third, the income-enhancing effects exhibit significant heterogeneity. The effects are more pronounced in high-income areas and in regions located farther from provincial capitals. In addition, when the leading industries of the parks are aligned with the main industries of local regional public brands of agricultural products, the positive impact on farmers’ income is stronger. Based on these findings, the government should appropriately expand the scale of Modern Agricultural Industrial Park construction to promote regional industrial development and increase farmers' income. It is also necessary to strengthen the coordination between the parks’ leading industries and local regional public brands, and to improve policy guidance in order to ensure long-term effectiveness and sustainable development.