The invention discloses a method for winterizing a winter power transmission line. The method comprises the steps: a, putting chlorosulfonated polyethylene into a container; b, adding organosilicone resin into the contained chlorosulfonated polyethylene, stirring, then allowing to stand for 30 minutes; c, adding a magnesium hydroxide powder, an antimonous oxide powder, a tetrafluoroethylene powderand an organic solvent to the container; d, heating the container to 130 DEG C, and stirring slowly; e, after the completion of heating, allowing to stand, and waiting for use; f, when cooling to 30DEG C, coating the power transmission line with the prepared coating; and g, temporarily increasing the current to make the line emit heat to thaw accumulated ice and accumulated snow on the line. Through reaction of chlorosulfonated polyethylene, organosilicone resin, the magnesium hydroxide powder, the antimonous oxide powder, the tetrafluoroethylene powder and the organic solvent in the environment of 130 DEG C, the coating is prepared, coats the power transmission line, and can effectively prevent icing and prevent breaking of the power transmission line.