A four-bar parallel palletizing robot is used as the object of research. The dynamic model of palletizing robot is established by using the Lagrange functional equilibrium method in robot dynamics. On the basis of classical Proportion Integral Derivative (PID) control, Iterative Learning Control (ILC) was used to compensate the unknown parameters and disturbances of the system, and the tracking control of the desired trajectory of each joint of the robot system was realized. Through the analysis and simulation of the control system, under the premise of stable operation of the robot system, the iterative learning rate was set to 0.75. After 10 iterations, the ratio of the maximum absolute value of the system error over the desired trajectory could be controlled below 10%. The experimental results show that the PID iterative learning tracking control of the palletizing robot can obtain quite high tracking precision.