Abstract: With the wide use of composite insulators, in-depth exploration of the contamination mechanism of composite insulators can provide scientific theoretical guidance for the selection, operation and maintenance of composite insulators. In this paper, the semi empirical mathematical expression of the collision rebound motion between micron particles and electrical silicone rubber is combined with the simulation of electric field and flow field, and the macro fouling model of composite insulators is established. At the same time, based on the charged pollution accumulation platform, an ideal pollution accumulation environment is constructed. The effectiveness of the model is verified by the comparison of pollution distribution and visualization. The results show that the pollution deposition morphology on the insulator surface is affected by the comprehensive action of physical field distribution and collision particle properties. Affected by the composite insulator structure, the tangential direction between the front end of the windward side mandrel on the upper surface of the insulator and the leeward side mandrel is the particle retention zone, and the front and rear sides of the lower surface mandrel are the particle retention zone. The model has reliable physical and experimental bases, and can display the pollution accumulation information of composite insulators more finely. This model can be used for the selection and optimization of composite insulators in the future.