The performance indexes of parameter matching are formulated and the concept of degree of hybridization is put forward based on a kind of driving system of hybrid electric vehicle,the effect of vehicle mass on vehicle performance is obtained by the calculation and analysis of the total power of power source and performance indexes.On this basis,the upper limit and lower limit of the degree of hybridization are calculated,on the basis of ADVISOR simulation platform,the simulation model based on NEDC cycle is built up,the simulation and analysis of the effect between different degree hybridization on the dynamic performance and fuel economy performance of the vehicle are accomplished.The results show that the fuel economy gets better and better along with the degree of hybridization increasing,but the dynamic performance of the vehicle gets worse gradually.According to the relationship between the fuel consumption of the vehicle and the degree of hybridization,the optimum degree of hybridization is confirmed by using twice linear fitting method,besides,the relevant parameter matching of the transmission is accomplished.