According to the driving cycle of heavy off-road vehicles, the brake power and energy permutation is analyzed, and the performance requirement for the hybrid energy storage system(HESS) is achieved based on the brake energy recovery rate and motor parameters. The parameter matching method for the HESS is proposed and by which the instance calculation for the hybrid propulsion system of 21 tons class vehicles is carried out, and the performance of the HESS with Li-ion cells and ultra capacitors is discussed too. The instance calculation and the test results indicate that the designed HESS can meet the requirement of the total performance of the HEV and the brake energy recovery, the volume and weight answer for the restriction of the top design of the HEV. The designed HESS with ultra capacitors can increase the transient power volume greatly and the brake performance and the brake energy recovery rate are enhanced remarkably.