This paper investigates the tracking control problem of robot manipulators with complex uncertainties and proposes an improved fixed-time nonsingular terminal sliding mode performance control (IFTSMPPC) method. Firstly, the barrier Lyapunov function and the prescribed performance function are used to jointly constrain the error state, and the prescribed performance function is used to constrain the transient and steady-state performance of the system. In addition, non singular terminal sliding mode control is incorporated into a fixed time control framework to improve system stability and conv...