A steer-by-wire control method is provided for a steer-by-wire system mounted in a vehicle that is equipped with an engine and a battery. The steer-by-wire control method stores a deviation angle between a steering angle and a turning angle in a non-volatile memory of the steer-by-wire system as a readable value when an ignition switch is switched from ON to OFF. The steer-by-wire control method further reads the deviation angle from the non-volatile memory when the ignition switch is switched from OFF to ON. The steer-by-wire control method further prohibits further reading of the deviation angle from the non-volatile memory after reading the deviation angle from the non-volatile memory and after reading the deviation angle from the non-volatile memory and after starting the steer-by-wire control.