The high-voltage post insulator is used for the insulation and supporting conductor in the high-voltage overhead transmission and distribution lines. Generally, it is divided into five grades of 6, 10, 15, 20 and 35kV according to the approved voltage. The post insulator is composed of porcelain parts and steel feet with no less than 525 Portland cement and porcelain sand adhesive. The surface of porcelain is white or brown, and the surface of steel foot is hot-dip galvanized. The post insulator shall be in accordance with the provisions of gb1000 "pin insulator for high voltage line" and gb772 "technical conditions for porcelain parts of high voltage pin insulator".