The invention discloses a sleeve motor steering-by-wire device and a control method, wherein the steering-by-wire device includes a steering wheel, a steering column connected to the steering wheel, a left wheel steering transmission mechanism connected to the left wheel, and a steering column connected to the right wheel. The connected right wheel steering transmission mechanism, and the mechanical steering transmission mechanism connected to the steering column through the electromagnetic clutch, the steering column is connected to the road sense / assist motor through the reducer, and the steering device also includes a steering by wire execution The steer-by-wire actuator includes a first sleeve motor, a second sleeve motor, and a planetary roller screw mechanism driven by the first sleeve motor and / or the second sleeve motor. The invention adopts a double-sleeve motor and a planetary roller screw mechanism, fully utilizes the axial space of the rack and the tie rod protective sleeve to reduce the radial size of the motor, and has high transmission efficiency, which is easy to improve the double-sleeve motor when working under heavy load. drive consistency.