Power-change type electric vehicle power on/off control system and method

The invention discloses a power-change type electric vehicle power on/off control system and method; the system comprises a vehicle mechanism and a vehicle control unit; the vehicle mechanism comprises the vehicle control unit, a battery management system, and a chassis batter locking mechanism; the vehicle control unit is used for detecting a battery locking signal sent by the chassis battery locking mechanism and a battery fast change signal sent by a battery fast change mechanism, controlling high/low voltage power on/off of the vehicle in a battery fast change process according to the battery locking signal and the battery fast change signal, and sending a permitted fast change order to the battery fast change mechanism; the battery fast change mechanism is used for replacing the cell pack in the battery manage system according to the permitted fast change order. The system and method can monitor the power change process of the vehicle; if the vehicle high voltage system is connected and electrified in the beginning of the power change process, the system and method can automatically disconnect the high voltage, thus improving efficiency and safety of the power change process.