Pollution rules of power transmission equipment exposing in the fog-haze environment has its own peculiarities. In order to study the duration of haze and smog components affecting the contamination of external insulation

the silicone rubber specimen and XP-70 insulators are used to simulate the contamination tests. The results show that the contamination rate in the fog-haze environment is fast and hard to reach saturation. Suspended particulate deposition play a major role in the contamination. The contamination rate in haze environment more quickly reaches saturation. Suspended proliferation and adhesion of the contamination particles play a major role. In addition

the increase of fog conductivity and dissolvable electrolyte in the haze promote the increase of contamination. Through the insulators test in the presence and absence of Kaolin

results show that the NSDD of insulators have a marginal impact on the ESDD growth in the fog-haze environment.