The invention provides a control circuit applied to an electric vehicle and a control method. The control circuit comprises a back cabin door detection switch, a first relay, a second relay and a high voltage electric switch. According to the control circuit, when a back cabin door is in an open state, the back cabin door detection switch is turned on, at this time, the coil of the first relay is powered on, the normally closed contact of the first relay is switched on, and an ON shift is disconnected with an electronic control unit, so that even if a driver turns the key to the ON shift, the vehicle cannot be powered on with the high voltage, and accordingly the problems that under the condition that a communication device is damaged or no communication device exists, a serviceman and the driver cannot communicate normally, the driver does not know about the maintenance progress in the vehicle and probably forcibly drives the electric vehicle to run, and thus higher potential safety hazards exist are solved.