Abstract: The super-hydrophobic surface has excellent hydrophobicity and self-cleaning properties. In this paper, the super-hydrophobic and hydrophobic silicone rubber surface with the same material were prepared, and the flashover test of polluted surface was designed and then carried out under fog wetting condition. The wetting state of the polluted surface, the dynamic behavior of water droplets and flashover voltage with AC electric field were observed, and the mechanism was investigated. The results show that after being wetted by fog, discrete droplets with a contact angle greater than 90° are formed on the polluted area of the super-hydrophobic surface, and droplets on the non-polluted area of the super-hydrophobic surface are smaller than the hydrophobic surface due to their need for stability. Under AC electric field, the decrease of the dielectric constant of the polluted water droplet leads to the increase of the electric field force, but at the same time the friction increases too, which further affects its dynamic behavior. Most polluted water droplets vibrate and deform, and some very small polluted droplets and clean droplets roll and coalesce. The flashover voltage of the prepared superhydrophobic surface is 58%, 109%, 108% higher than that of the hydrophobic surface when placed at the angle of 0°, 10°, 20°. The results are of great significance for the application of super-hydrophobic surface in power equipment.