Electric vehicle and method in an emergency

PURPOSE: An electric vehicle and a controlling method an emergency thereof are provided to guarantee the safety of an operator by preventing an accident. CONSTITUTION: A sensor unit senses the state of a vehicle. A motor controller(150) operates the vehicle by controlling a motor. A PRA(Power Relay Assemply)(160) supplies battery power to the motor controller. A main control unit(110) controls the operation of the vehicle corresponding to data inputted from the sensor and an interface unit. A sub control unit(120) monitors an operation state from the main control unit. The sub control unit performs emergency control instead of the main control unit in an unusual condition of the main control unit. The main control unit and the sub control unit block a power source which is applied from a battery to the motor controller by controlling the PRA in the unusual condition of the main control unit.