The invention discloses an ice and snow melting device for a transmission line, which comprises a hot air pipe. The hot air pipe comprises a heating pipe, U-type baffles, a PTC heating element and a power line, wherein two ports of the heating pipe are sealed; the top surface at the right end part of the heating pipe is provided with an air inlet pipe; the bottom surface at the left end part of the heating pipe is provided with a downward air outlet; the PTC heating element is arranged in the cavity of the heating pipe between the air inlet pipe and the air outlet, and a power line is also provided; an insulated piece is arranged between the PTC heating element and the inner wall of the heating pipe; and the two U-type baffles are respectively fixed at the right end part and the left end part of the heating pipe, and the opening of each U-type baffle faces downwardly. The air is heated and compressed through the PTC heating element, the hot air melts ice and snow on the transmission line, overheat protection is carried out on the transmission line, the transmission line can be prevented being hit and vibrated, and the maintenance efficiency is improved.