The invention relates to a permanent magnet motor sealing technology, in particular to a rotor sealing structure of a locomotive permanent magnet synchronous traction motor. The technical problems that the cooling effect of a machine shell of an existing permanent magnet motor is poor, and a matched cooling system is complex in structure are solved. The rotor sealing structure of the locomotive permanent magnet synchronous traction motor comprises a machine base, a rotor iron core, a stator iron core, a non-transmission end cover and a transmission end cover; the inner sides of the non-transmission end cover and the inner side of the transmission end cover extend towards the inside of the motor and are in compression butt joint with the positions, close to the inner circle, of end plates at the two sides of the stator iron core; sealing strips are fixed between the extending structures of the non-transmission end cover and the transmission end cover and the stator end plates, annular sealing plates are further arranged between the sealing strips and the stator end plates, and then the rotor iron core is sealed by the sealing plates and the sealing strips together. According to therotor sealing structure, cooling air cannot enter a rotor part, so that foreign matter in the cooling air is prevented from being adsorbed on the surface of a rotor, and the technical risk caused whena locomotive motor uses a permanent magnet motor is reduced.