The data communication between the electric vehicle and the AC charging post is carried out by using the CAN bus. When the charging interface is docked, the electric vehicle sends data to the charging post through the CAN bus, which contains the identity information of the vehicle itself and the charging status information of the on-board battery. Since the CAN bus can only store up to 8 bytes of data per packet at a time when transmitting data, and the data sent by the electric vehicle to the charging pile exceeds 8 bytes each time, the data is divided into two packets, and the two packets are packaged and sent together each time. The data sent from the AC charging pile to the operation management system contains two categories: charging status and charging history.