Abstract: Enhancing the level of socialized services for agricultural machinery and refining the agricultural socialization service system are key to fostering an effective linkage between small farmers and modern agriculture. This study utilizes panel data from 31 provinces (including municipalities and autonomous regions) (not including Hong Kong, Macao and Taiwan) in China from 1997 to 2022 to evaluate the impact of establishing major grain-producing areas on agricultural machinery socialization services, employing a difference-in-differences (DID) model for analysis. The findings indicate that designating major grain-producing areas positively supports the development of these services. Additionally, such designations contribute to increasing farmers' incomes, promoting technological advancements in agriculture, and improving market openness, which indirectly foster the growth of agricultural machinery socialization services. The policy of establishing major grain-producing areas has a significantly different impact on agricultural machinery socialization services across regions, with a stronger positive effect observed in the central and western regions compared to the eastern region. To further promote the development of agricultural machinery socialization services and achieve balanced progress in agricultural modernization, this study recommends deepening the implementation of the main grain-producing areas policy and enhancing regional adaptation. Strengthening the linkages between income growth and technological advancement in agriculture, promoting agricultural market reform and structural reforms on the supply side of agricultural machinery services, and optimizing regional coordination mechanisms are also advised to achieve a balanced development of these services.