Abstract: With regard to the presence of actuator faults in linear constant delay systems, we propose an active fault-tolerant control scheme based on trajectory-tracking. The aim is to design a fault-tolerant control law and a fault observer to ensure the tracking of the states of faulty systems to reference models even if faults occur. The fault-tolerant control law is designed to compensate for the actuator faults; The proportional integral observer is introduced to acquire information related to the fault. The dynamics of the state, as well as the tracking, fault estimation, and output estimation errors, comprise the descriptor system. In addition, using the Lypapunov-Krasovskii theorem, the stability problem of the descriptor system can be solved easily in terms of the linear matrix inequality (LMI) to obtain the observer gain matrix and control law. Finally, a numerical example is considered to compare the tracking performance of the proposed fault-tolerant control approach with the classic approach and to illustrate the effectiveness of the proposed scheme.