The utility model discloses a thunder-proof column insulator. The thunder-proof column insulator includes a wire clamping hardware fitting, which comprises an upper pressing block and a lower pressing block, wherein a first groove is disposed on an upper end surface of the lower pressing block, a second groove corresponding to the first groove is disposed at a lower end surface of the upper pressing block, and the first groove and the second groove are provided with corresponding piercing teeth. The thunder-proof column insulator is characterized in that: an upper end surface of the upper pressing block is provided with a third groove which corresponds to the second groove, an opening diameter of the third groove is different from that of the second groove, and piercing teeth corresponding to the piercing teeth in the second groove are disposed in the third groove. The thunder-proof column insulator is suitable for wire clamping hardware fittings with different cross sections, and needs no maintenance.