Abstract:A efficiency model of the multi-range composite CVT system working on the positive and negative phases was established. The relation curves between overall efficiency of the multi-range composite CVT system and transmission ratio of metal pushing V-belt CVT, transmission torque and input rotate speed, were obtained by simulation. The simulated results indicated that no matter the CVT system works on positive or negative phase, the system efficiency increases with the CVT transmission ratio, torque or input speed increased. The efficiency is higher than that of metal pushing V-belt CVT system obviously. Furthermore, the system can be applied in high-power vehicle transmission, which enlarges the speed ratio range of transmission and increases the overall power.