Abstract: Agricultural tractor load is the main parameter that affects the working performance of the tractor engine indicators, which directly affects the field efficiency and working performance of agricultural tractors. Relevant studies have shown that efficient tractor operation can be achieved when at least 80% of the tractor engine power is used and when the engine speed is low. In this study, the engine load parameters of Massey Ferguson MF 8480 were tested in a controlled manner during field crop harvesting. A mathematical model was constructed to reflect the relationship between engine power, engine speed and fuel consumption characteristics, giving the working time and fuel consumption distribution at different engine speeds during the operation of the agricultural tractor. The analysis of engine speed and load pattern reveals the relationship between tractor operating efficiency and the operation of each engine parameter in the field. The results of the study are intended to provide a theoretical basis and reference for the study of the relationship between the engine operating parameters of agricultural tractors and the improvement of field operating efficiency.