Silicone rubber composite insulator has the advantages of high mechanical strength, excellent antipollution flashover performance, light weight, convenient operation and maintenance. It has been widely used in power grid construction. As silicone rubber material has excellent hydrophobicity and hydrophobicity mobility, its surface can still maintain good antifouling flashover ability after contamination. In some industrial areas, there is special industrial dust pollution, and the special industrial dust pollution in such areas has obvious impact on the performance of composite insulators, which makes the composite insulator surface in operation more prone to fouling. After fouling the hydrophobicity of the insulator surface is significantly reduced and the insulation performance is weakened. In order to study the natural pollution characteristics of composite insulators in special industrial dust areas, the composite insulators operated in a special industrial park in Jiangsu are sampled to study the pollution characteristics. The results show that the surface contamination of composite insulators operating in this area is generally heavy, the density of pollution equivalent salt is high, and the soluble salt components of pollution are mainly CaSO₄ and Na₂SO₄. The main components of insoluble ash are C, O, Si, containing carbon powder, SiO₂, CaO and other substances, which affect the surface conductivity and absorption of insulators.