Aiming at the trajectory tracking control of the palletizing manipulator, a nonlinear sliding mode control method is proposed. Firstly, the Newton-Euler method is used to derive the dynamic model of the palletizing manipulator, which is then equivalent to a discrete form. Then, the nonlinear terminal sliding mode surface is designed to accelerate the convergence speed of the joint angles, and the equivalent reaching law is introduced to suppress the chattering effect of the system. At the same time, the problem of parameter tuning of the controller is solved with the help of the glowworm swarm optimization algorithm which is used to obtain the optimal control performance. Finally, the effectiveness of the proposed control method in this paper is verified by simulation and experiment. The results show that the control method in this paper has higher tracking accuracy than integral sliding mode control, and can ensure that the palletizing manipulator can better track the upper reference trajectory, which has certain engineering application value.