Abstract The socialized service of agricultural machinery is an important way for small farmers to organically connect with modern agricultural production, and is of profound significance for promoting rural revitalization. Based on the theoretical analysis of the impact of agricultural subsidies on farmers’ purchase of agricultural machinery services, this paper uses the third term unbalanced panel data of CLDS2014-2018, panel ordered Logit random effect model, ERM model and intermediary effect model to prove that agricultural subsidies can significantly promote farmers’ purchase of agricultural machinery services. And after different robustness tests and instrumental variable methods, this conclusion is still supported. Heterogeneity analysis shows that agricultural subsidies play a greater role in purchasing agricultural machinery services in small-scale, low-income and non-major grain producing areas. Further mechanism tests show that agricultural subsidies can not only significantly promote farmers to engage in agricultural production, but also enhance the availability of credit and be used for productive investment, expand the actual grain growing area and alleviate financial pressure. Thus, it can promote farmers to purchase agricultural machinery services. This study helps us to understand the internal mechanism between agricultural subsidies and the purchase of agricultural machinery services and provides inspiration for the government to improve agricultural subsidy policies in the process of promoting agricultural socialized services.