Torque tightening and dismantling device for large compression nut

The utility model discloses a torque tightening and dismantling device for a large compression nut. The torque tightening and dismantling device comprises a gear sleeve, a fixed disk, a driving sleeve and a torque spanner. The gear sleeve is a cylinder and is fixed to the outer portion of the torque spanner in a sleeved mode. The fixed disk is a disk with a center hole. The fixed disk is fixed to a bolt. The center hole is square. An output shaft is inserted in the center hole to be fixed. The gear sleeve is arranged in an opening at one end of the driving sleeve to be fixed. A nut to be mounted or demounted on the bolt is fixed into an opening at the other end of the driving sleeve. According to the torque tightening and dismantling device, an original torque output mechanism of the torque spanner is used as a reactive force arm structure, so the problem that a large nut and bolt mechanism can not be tightened without a reactive force arm supporting point in an open environment is solved; since the nut tightening problem is solved, safe operation of a product is guaranteed, and the labor intensity of workers is also greatly lowered.