Electro-mechanical transmission (EMT), with power distribution strategy as its core technology, stands for the developing orientation of the heavy vehicles transmission, which is able to fulfill power, fuel economy and electricity demand of the vehicles.In this paper, the mechanical and electrical power balance equations were established according to the split and convergence characteristics of the power coupling mechanism and power distribution unit.The power demand of the EMT is predicted through combination of the fixed-gain prediction algorithms and the input that drivers desired speed during the vehicle driving cycle.Then the optimal power distribution strategy based on finite horizon power prediction algorithm is achieved.Moreover, the optimal allocation pattern of the engine and motors is proposed.The rationality of control strategy is verified by the forward simulation results.