This paper aims to discuss fixed-time tracking control problem for a nonholonomic wheeled mobile robot based on visual servoing. At first, by making use of the pinhole camera model, the robot system model with uncalibrated camera parameters is given. Then, the tracking error system between the mobile robot and desired trajectory is proposed. Thirdly, on the basis of fixed-time control theory and Lyapunov stability analysis, fixed-time tracking control laws are proposed for the mobile robot such that the robot can track the reference trajectory in a fixed time. It is well known that the convergence time for the finite-time control systems is usually dependent on the initial state of the system. However, the settling time obtained by the fixed-time control is independent of the system initial conditions and only determined by the controller parameters, which is more in line with practical application. Simulation results are given at the end.