The utility model discloses an apparatus for disassembling axle pin, round pin axle install in round pin shaft hole base, and the tip of round pin axle is equipped with the screw hole, and dismounting device includes: supporting a section of thick bamboo, supporting the first end opening of a section of thick bamboo, the second end seals, and the center department that supports the second end of a section of thick bamboo is equipped with first through -hole, and the first end butt that supports a section of thick bamboo is on round pin shaft hole base's side, the jack, the center department of jack is equipped with the second through -hole, and the terminal surface butt of side of jack and the second end that supports a section of thick bamboo, the guide arm, the first end of guide arm is equipped with the external screw thread, and the guide arm passes the jack in proper order and supports a section of thick bamboo to the first end and the screw hole of round pin axle of guide arm are connected, and the second of guide arm is served and is equipped with the lock piece. The utility model discloses a dismounting device can guarantee round pin axle and round pin shaft hole base card extremely occasionally sufficient effort extract it, can guarantee again that round pin axle not canceling shaft hole base when extracting leads to the fact the injury, simple structure, convenient operation, safety and stability.