In this paper, the fundamental structure of charge and discharge device of V2G is analyzed. As for three phase voltage source PWM converter’s control, this paper presents that the control strategy of direct power control PWM rectifier is adopted under charging operation and constant power control strategy is used under discharging operation. For bidirectional DC/DC converter control strategy, dual closed-loop control of external voltage loop and internal current loop is put into use. The whole system of charge and discharge device of V2G is modeled and simulated by using the toolbox of PSCAD/EMTDC. Two-way power energy and information interaction of electric vehicle and power grid has been realized, current harmonic on grid side is decreased, power factor and power quality are improved.