Abstract: Surface micro structure is a key influence factor on surface flashover of insulators. This paper studied the construction methods of micro-structure on polymer insulators as well as its effect on surface flashover characteristics. Firstly, taking SiO₂ micro balls as template, the method of chemical templating was applied to realize the construction of micro holes on the surface of CLPS. The effect of diameters of SiO₂ ball and volume of addition on the morphology was also studied. Secondly, laser micro treatment was used to construct triangular grooves in hundreds of microns on the surface of PMMA insulators and the influence of laser parameters on the morphology and structure of micro grooves was explored as well. Surface flashover test of the insulators with the aforementioned micro structure in different scales was conducted on a short-pulsed high voltage platform. The results show there was a big increase in surface hole-off voltage. Compared with the traditional surface roughness treatment by polishing, the construction of micro structure on the surface of polymer in this paper is controllable and the increase of flashover voltages is stable.