Abstract: :With the increasing popularity of electric vehicle, regular charging using charging piles installed in residential parking lot, public parking lot, unit parking lot and other areal will become the mainstream mode of electric vehicle charging. Large-scale distributed charging is bound to have an impact on the voltage quality of distribution network. This paper summarizes the types of electric vehicle chargers and charging modes, and the voltage quality problems of distribution network caused by large-scale electric vehicle charging, which include such issues as harmonic pollution, voltage drops and three-phase voltage imbalance. The influences of the control strategy of orderly charging, the coordination control of electric vehicle charging and distributed power supply, and the V2G model on the voltage quality improving of distribution network are explored, and the next research work in related fields is looked forward to.