The effect of saving fuel and reducing emissions for hybrid electric vehicle(HEV) should be obvious, and the most realistic solution was to develop heavy HEV. Based on the concepts of dynamic servo and electromagnetic coupling, the project of mechanical-power- penetrated double motors was proposed and the heavy HEV was developed. Meanwhile, the powertrain system structure, working principle and control strategy of the HEV were analyzed. The model of the vehicle was built with Matlab/Simulink, and the output torques of engine, motor and the double rotor generator were simulated. The experiments of the outer characteristics and working efficiency of the motor were carried out on the test bench. The research results indicate that the simulation of output torques can meet with the cycle conditions well. The output efficiency of motor is high and can be achieved 86%, which can meet with the HEV’s design requirements. All of above that can provide reference for the calibration and matching of the electromagnetic coupling HEV in future.