The core function of BMS is to detect information such as battery voltage, charge and discharge current and temperature, and calculate the state of charge of the battery to select or adjust the charge and discharge method, and to determine whether it is necessary to turn on the balance management, and to protect the battery according to the abnormal state, Ensure battery safety and extend battery life. The key technology of CAN bus includes two aspects, hardware and software. Hardware includes: microcontroller, CAN controller and CAN transceiver. The software includes node control program and CAN bus network application layer protocol.