The invention discloses an intelligent automobile redundant steer-by-wire device and a control method thereof. The intelligent automobile redundant steer-by-wire device comprises a steering wheel, a steering column, a road sensing motor, an electromagnetic clutch, a redundant motor, a gear rack steering gear, a power-assisted motor and a control unit, and the steering wheel is assembled at the topend of the steering column; and the road sensing motor, the electromagnetic clutch, the redundant motor and the gear rack steering gear are sequentially assembled on the steering column. The controlmethod comprises the steps that the steering device starts to work only when it is detected that a vehicle is started, and the steering device comprises two working modes and corresponding control methods, namely the driving auxiliary mode control method and the the automatic driving mode control method. The intelligent automobile redundant steer-by-wire device and a control method thereof have the advantages that redundant backup of the sensor, the motor, the control unit and the power source is achieved, and the service life can be prolonged. When slave ECU monitors that master ECU fails, the control right is taken over immediately, other structures are not needed, and seamless switching of the control right is easy to realize.