Energy conservation and emission reduction is an important task in the research field of green agricultural machinery. Tractors are the main agricultural driving forces but the emission is a major problem. In particular, there are many small and medium tractors which have a large number of emissions. Electric tractors are new research hotspots, especially suitable for small plots, greenhouses and hilly areas. One of the problems of electric tractors is that the work mileage is short and the temporary charging is inconvenient. So the extended range electric tractors are derived，that is to add a range extender made up of a diesel engine and generator to extend the tractor working time in time. The control strategy of extended range electric tractors was studied, and a forward predictive control model of the motor power was proposed. The modeling and simulation research was carried out. Through the comparison and analysis, it was found that the introduction of the forward predictive control model can improve the following of low speed, the response of acceleration and the starting characteristics of the range extender at high speed. At the same time, when the descending gradient of the motor power demand was very large, the prediction of power lag can be beneficial to the stable operation and smooth unloading of the range extender. Then from the angle of optimization and calibration of the engine startup control strategy, the test research and analysis were carried out on the startup ride comfort, the success rate and the energy consumption of the range extender, and the method of startup control and the optimum drag speed (1000r/min) were determined by improving the speed of the dragging target, the exit time of the motor drive and the optimization of the fuel injection, so that the ride comfort and the startup success rate were obviously improved, and the startup energy consumption was reduced.