The researching hybrid electric vehicle（ HEV） is the double axle torque combination style parallel hybrid electric vehicle,and the SC7130 car is taken as design object and the new type continuously variable transmission（ CVT） system with reflux power is used in it. After the new type continuously variable transmission system with reflux power is researched and analyzed,the structure layout of the overall vehicle is established,then,the main operation mode of the transmission system is formulated. The bond graph model of the overall vehicle transmission system is built by the application of the bond graph theory. According to the bond graph model of the overall vehicle transmission system,the state equation（ the mathematics model of the overall transmission system） is listed. The simulation model of the transmission system is set up by using Matlab / Simulink,and the speed ratio control strategies of each gear are formulated. The transmission system is simulated.The transmission system parameters are optimized further after the performances（ such as dynamic and economic performances） analysis of the overall vehicle.