The invention relates to a box for carrying and protecting a salt density test bottle on an electric transmission line. A box body comprises an upper box body and a lower box body which are correspondingly arranged, an upper partition board and a lower partition board are respectively arranged in the upper box body and the lower box body, and circular arc-shaped partition board grooves are formed in the upper partition board and the lower partition board; a sealing strip is mounted at the contact gap of the upper box body and the lower box body, a steel wire rope is mounted on the buckle outer edge of the upper box body and the lower box body, one end of the upper box body or one end of the lower box body is connected to a lifting hook, and the lifting hook is connected with the steel wire rope. The box is light and compact and convenient to lift and transport, is benefit for placement, is good in protection function for the salt density test bottle and good in sealing effect, and is beneficial for guaranteeing the accuracy of extracted numerical values, so that the work efficiency is greatly improved, and the safety and reliability of changing and testing the salt density test bottle on the line are guaranteed.