In recent years

algae overgrowth have been found on the surface of composite insulators and RTV（room temperature vulcanization）coatings in the humid and hot area in southern China

which greatly reduces the hydrophobicity of the composite insulating materials and affects their electrical properties. It is difficult for the traditional insulator cleaning method to eradicate the biological contamination pollution layer. Chlorella vulgaris

which is usually found on the surface of insulators

is used as the study object in this paper. The growth of algal cell after spraying the algicide is characterized by such test methods as cell destruction rate

photo synthetic activity and chlorophyll a mass concentration to explore the inhibition effect of spraying algicide on algae growth on the high temperature vulcanized silicone rubber. It is found by study that with 1427 liquor（tetradecyl dimethly benzyl ammonium chloride）with molar mass fraction of 0.025 mol/L as algicide in this experiment

there is an inactivation effect on chlorella vulgaris with unit area density of 2.5×10~7cells/cm~2when the dosage of algicide is greater than 0.2 μL/cm~2.The higher the dose of algicide is

the higher the algae inactivation efficiency is. Algicide would first inhibit algal photosynthetic activity

causing cell rupture and chlorophyll reduction and finally resulting in the complete decomposition of algae. A good inhibitory effect on the attached algal cells can be obtained within at least 10 days when the algicide dose is 0.4 μL/cm~2or above. For application at site

the algicide dose of 0.4 μL/cm~2can be used to inactivate and inhibit the growth of algae on the insulator surface.