Continuously Variable Transmission （CVT） equipped vehicle improves its power performance by ensure the engine works on its peak power point under each throttle angle. This method didn’t pay any attention to the CVT efficiency, which also has influences on power performance of the system. Based on the analysis of how CVT efficiency influences power performance of the system, an optimal algorithm is proposed to calculate the target CVT ratio to achieve maximum power performance with consideration of CVT efficiency. A simulation model is established to validate the optimal algorithm. Simulation results indicate that the acceleration time from 0 km to 100 km of the system veduced by 0.63 s.