This study investigates the impact of the adoption mode of agricultural machinery (AM) on food productivity in China, using data from 795 grain farmers in the North China Plain. The research finds that self-purchase (SP) of AM improves technical efficiency but reduces input efficiency compared to service outsourcing (SO). The effect is driven by the opportunistic behavior of AM suppliers and labor supervision issues, which lead to a decline in the quality of AM operations. The impact of AM adoption mode on food productivity varies among different types of farmers. Large-scale and professional farmers benefit more from SP, while small-scale and part-time farmers benefit more from SO. The study suggests that the Chinese government should adjust its agricultural machinery subsidy policy and reduce transaction costs to mitigate the loss of technical efficiency caused by AM suppliers' opportunistic behavior. The findings highlight the need for a balanced approach to AM adoption, considering both technical and input efficiency, and the specific characteristics of different farmer types.This study investigates the impact of the adoption mode of agricultural machinery (AM) on food productivity in China, using data from 795 grain farmers in the North China Plain. The research finds that self-purchase (SP) of AM improves technical efficiency but reduces input efficiency compared to service outsourcing (SO). The effect is driven by the opportunistic behavior of AM suppliers and labor supervision issues, which lead to a decline in the quality of AM operations. The impact of AM adoption mode on food productivity varies among different types of farmers. Large-scale and professional farmers benefit more from SP, while small-scale and part-time farmers benefit more from SO. The study suggests that the Chinese government should adjust its agricultural machinery subsidy policy and reduce transaction costs to mitigate the loss of technical efficiency caused by AM suppliers' opportunistic behavior. The findings highlight the need for a balanced approach to AM adoption, considering both technical and input efficiency, and the specific characteristics of different farmer types.