In this article, an adaptive fuzzy fixed-time fault-tolerant control is developed for a steer-by-wire system with actuator fault, input hysteresis, and full-state constraints. Firstly, a dynamic model of the steer-by-wire system considering actuator fault input hysteresis is formulated. The input hysteresis, caused by factors such as the electromagnetic characteristics of the steering motor, mechanical transmission clearance and the delay in sensor signal processing, is characterized using a backlash model. Actuator faults are modeled by incorporating effectiveness factors and bias faults, which reflect the performance degradation and deviation of the steering motor. Then, based on backstepping control theory, fuzzy logic system, and adaptive technology, the compensation method for actuator fault and input hysteresis is designed. In this method, the fuzzy logic system is employed to approximate the unknown nonlinearities in the system, while the adaptive law is designed to update only a single global parameter in real time, thereby effectively reducing computational complexity. To ensure that the system states always remain within predefined constraint boundaries, the barrier Lyapunov functions are introduced to incorporate the constraint conditions of the front wheel angle and its rate of change into the control law design. The method is then analyzed from the perspectives of safety, actuator feasibility, and driving comfort. On this basis, a fixed-time controller is constructed to ensure that the system tracking error converges to a bounded compact set within a fixed time, thereby effectively improving the control accuracy and reliability of the closed-loop system under the influence of complex factors. The experimental results show that the states of the proposed method do not exceed the bounds under both classic scenarios, including double lane change and sharp turn, as well as extreme conditions on a low adhesion road surface. Furthermore, the average maximum error and average root mean square error are 0.038 and 0.006 rad, respectively, which are obviously superior to other methods in existing literature.