The invention discloses an engine control method for a tractor and belongs to the technical field of engine control and primarily solves the technical problem that the tractor is poor in ability of overcoming loads when the rotating speed of the engine is reduced. The engine control method comprises the following steps: when the rotating speed of the engine is not smaller than a first threshold value, outputting engine power along with change of engine torque; and when the rotating speed of the engine is smaller than the first threshold value, outputting the engine torque at a fixed value andoutputting the engine power linearly along with the rotating speed of the engine. According to the engine control method, when the rotating speed of the engine decreases from a calibrated rotating speed to the first threshold value, the engine power is increased first to the maximum power and then is decreased, and when the rotating speed of the engine is smaller than the first threshold value, the engine torque is output at the fixed value, so that the tractor is high in ability of overcoming the loads.