Abstract: Aimed at the single motor plug-in hybrid electric vehicle with CVT，an optimal control strategy for vehi-cle comprehensive performance is proposed． The CVT target speed ratio of each working mode is obtained through the optimization of system efficiency so that the vehicle energy consumption is improved． In order to solve the pro-blem of the vehicle ride comfort variation caused by the change of target speed ratio in mode switching，the vehicle ride comfort is adopted for improvement by limiting the change rate of CVT speed ratio，which，however，will pro-duce an effect on the speed of a car in its desired speed following． Therefore，by using PID controller which com-pensates the motor torque，a weighting function formed by the fuel economy，ride comfort and speed following is constructed，the parameters of PID controller based on Genetic Algorithm are optimized under the New Europe Dri-ving Cycle and multi-objective comprehensive evaluation through comparison between and analysis of the simulation results of a vehicle is conducted． The simulation results demonstrate that the method can effectively improve the ve-hicle comprehensive performance，including fuel economy，ride comfort and speed following．

Key words: plug-in hybrid electric vehicle, fuel economy, comfort, control strategy, target speed ratio, Genetic Algorithm, PID controller, weighting function