A simple and effective control method for robot trajectory tracking with uncertain dynamics was presented. The core idea of the proposed method was to modify the reference trajectory in real-time. The main operation of this method was to accumulate the generated tracking errors and compensate them feedforward in real-time to the points to be tracked on the reference trajectory. Firstly, the control block diagram for the proposed method was showed. Then, the equation for the relationship between the tracking error and the command error was derived from the control block diagram. The equation showed that the control algorithm in the controller only needed to ensure that the velocity error was stable and the tracking error would converge. The increase in compensation gain can also accelerate the convergence of the error. Subsequently, the convergence condition that PD control law can satisfy the proposed method was analyzed. At the same time, the adjustment scheme of parameters in the proposed method was given. Finally, the effectiveness of the proposed method was verified by simulation and physical experiment. In the physical experiment, the absolute value of error obtained from tracking trajectory 1 of each joint was no more than 0.0087rad; the absolute value of error obtained from tracking trajectory 2 of each joint was no more than 0.0059rad.