Abstract: In this paper, the force and motion process of the heavy and light object of the circular pendulum are analyzed. Not only the theoretical model describing the motion of entire circular pendulum system is constructed, but also the differential equations of the light object and the heavy object motions are obtained. Based on Euler algorithm, MATLAB software is used to solve the theoretical model, which can effectively simulate the motion behavior of the circular pendulum. In this paper, we have studied the impact of balance weight ratio on the motion of the circular pendulum, and combined the experiment to verify the theoretical model. The numerical simulation and experiment results are in line with each other, indicating that the theoretical model is effective within the allowable error range. These works can provide a reference for experimental design of the circular pendulum, and can also theoretically predict the influence of different parameter changes on the motion of the circular pendulum system.