Abstract: The improvement of agricultural production efficiency is an important way to ensure food security. Under the background of the rapid development of agricultural machinery service, the relationship between agricultural machinery service and food production efficiency is explored, so as to promote the common development of agricultural machinery service and food production. Based on the survey data of 591 farmers in Henan Province, this paper used three-stage DEA model and Tobit model to explore the impact of agricultural machinery socialization service adoption on farmers’ grain production efficiency, and further analyzed the moderating effect of cultivated land resource endowment. The results showed that the adoption degree of agricultural machinery socialization service could effectively promote the improvement of farmers’ grain production efficiency, the degree and quality of farmland fragmentation could play a negative and positive moderating role in the impact of degree of agricultural machinery socialization service on grain production efficiency of farmers. The effect of agricultural machinery service on grain production efficiency is limited by cultivated land endowment. Therefore, the government should increase subsidies for agricultural machinery purchase, speed up the process of cultivated land transfer and increase the fertility of cultivated land so as to promote the improvement of grain production efficiency.