Underwater installing method for support positioning structure of irradiation monitoring pipe

The invention relates to the technical field of inspection on nuclear power station equipment, in particular discloses an underwater installing method for a support positioning structure of an irradiation monitoring pipe, which comprises the following steps of: simulating a hanging basket on a water surface to react a mirror image of installation position information in an underwater irradiation environment that workers can not enter to the water surface, and then installing the mirror image into water after the mirror image is adjusted on the water surface, thereby transplanting the adjusting precision on the water to an underwater position. Therefore, the method solves the problem that personnel can not directly carry out equipment installing precision adjustment on members in a stack in a process of inspecting the member in a nuclear reactor or a pressure container reactor, and also ensures the underwater remote installation precision of equipment.