In order to solve the problem of surface aging and loss of hydrophobicity of the outer insulating composite material of power transmission and transformation equipment after a period of operation, the surface of the composite insulator is cleaned by a laser cleaning method. A laser cleaning platform was established. By comparing the water repellency analysis before and after cleaning and after wiping the surface, the feasibility of the laser cleaning process of silicon rubber on the surface of the aging insulator is verified. And according to the different light absorption ability of different colors and materials, the auxiliary cleaning effect of different colors and different materials when the auxiliary colorant is coated on the surface of the insulator is evaluated, including water repellency measurement, roughness measurement, cleaning depth measurement and 200 times microscope observation. The research results show that for the cleaning and activation of aging silicone rubber on the surface of composite insulators, the hydrophobic recovery effect achieved by the laser cleaning method is very obvious. In addition, the colorant with a large light absorption coefficient has a great auxiliary cleaning effect, and the cleaning effect of the non-glossy colorant is better than that of the gloss colorant when it is coated on the surface of the insulator.

external insulation; laser cleaning; water repellency; auxiliary colorant; light absorption coefficient