Abstract: In this study, we propose a weighted fast terminal sliding mode active fault-tolerant control for nonlinear robotic systems subject to actuator faults. Firstly, the actuator faults in the robotic system are estimated using an observer, and the unknown boundary of the actuator faults is estimated by an adaptive law. In order to compensate for the estimated actuator faults, a fast terminal sliding mode controller is designed according to the weighted position error of each joint. Consequently, the finite-time active fault-tolerant control is achieved. The Lyapunov function method is used to prove the stability of the closed-loop system, and a two-joint robot is used to verify the effectiveness of the proposed scheme. Our experimental results showed that the proposed scheme can compensate for the actuator faults by assigning weight values to different joint position errors. Thus, the position tracking error of the robot can converge fast in a finite time, and the tracking accuracy can be improved.