Abstract: The deposition of contamination particles on the composite insulators surface affects the electrical characteristics of insulators, resulting in surface discharge and even pollution flashover. Thus, exploring the deposition mechanism from a microscopic perspective can provide a theoretical basis for the stable operation of the power system. Based on the JKR contact mechanics theory, this study analyzes the force in the process of particle collision by the traditional Newton mechanics method and discrete element analysis method, respectively, and a collision deposition model that integrates normal collision and particle rebound velocity is proposed. Simulation experiments are carried out according to different collision deposition models, and the results are compared with the existing experimental results. The results show that the collision deposition model obtained by the discrete element analysis method is more accurate in predicting the deposition of S_iO₂ particles on the surface of composite insulators compared with the Newtonian mechanics method. The particle deposition number on the insulator surface tends to increase first and then decrease with the increase of particle size and reaches the maximum at the particle size of 20 μm. When the wind direction is changed, the ratio of NSDD between the medium voltage end and high voltage end of the insulator string will decrease with the increasing wind angle, and the ratio of NSDD between the lower surface and upper surface will decrease with the increasing angle. The particle deposition number on the insulator surface tends to increase first and then decrease with the increase of wind speed and reaches the maximum at ±30º. The model can more accurately describe the deposition process of pollution particles on the insulator surface, and the research results can help to improve the mechanism of pollution deposition on the composite insulator surface.