The vehicle steering system has successively gone through several stages of mechanical steering, hydraulic power steering and electric power steering. However, the electric power steering system(EPS) and the electronically controlled hydraulic power steering system(EHPS) cannot meet the steering technology demands of smart cars. As one of the important systems of the intelligent chassis-by-wire, the steer-by-wire system is an indispensable intelligent steering system in the smart car architecture. In order to analyze the key technologies and development trends of steer-by-wire, this review will start from the overview of the development of steer-by-wire and the key software and hardware technologies of the steer-by-wire system which includs the comparative analysis of 4 road feeling control, the application of strategies use intelligent algorithms in closed-loop steer control and dual-motor cooperative control strategies, vehicle stability control based on active front-wheel steering in steer-by-wire, functional safety-oriented software redundancy schemes and hardware redundancy schemes. Finally, the future research trend of the steer-by-wire system is prospected. It can be pointed that the steer-by-wire system will be developed in the direction of real comfort, precision and speed, safe and reliable appliction, and integrated control.