The invention provides an electric vehicle automatic charging system and method, and relates to the field of electric vehicle charging. The electric vehicle automatic charging system comprises a charger, a mechanical arm and a client side, wherein the charger is provided with a control unit and a charging gun, the client side and the charger are provided with WIFI modules respectively, the mechanical arm is correspondingly provided with a mechanical arm control system, the mechanical arm control system is in communication connection with the control unit of the charger, and a working end of the mechanical arm is connected with the charging gun. The disclosed automatic charging system applies a mature automatic mechanical arm technology in the field of industrial control to the technical field of charging, and eliminates an industrial pain point of the field of charging. After driving a car into a charging parking area, a client only needs to select automatic charging on a mobile phoneclient, the automatic charging system can automatically complete a series of charging processes such as gun taking, gun inserting, gun drawing and homing and the like, after charging is completed, theclient can also complete the payment on the mobile phone client; and the electric vehicle automatic charging system can provide convenient and user-friendly charging experience for the client.