Quick positioning device for upside-down hanging square steel column in reverse building method construction and construction method

The rapid positioning device comprises a square ring sleeve which is an opening type ring sleeve and used for being arranged on an upper square steel column in a sleeving mode, the square ring sleeve comprises a connecting part and an adjusting part, the connecting part and the upper square steel column are temporarily fixed, the adjusting part extends in the height direction of the upper square steel column, and the adjusting part is used for adjusting the height of the upper square steel column. A fixed distance l exists between the inner diameter of the adjusting part and the outer diameter of the upper square steel column; the cable pulling structure is connected with the square ring sleeve and used for pulling the square ring sleeve to slide up and down along the upper square steel column; the adjusting structure is arranged on the four side plates of the adjusting part and can move in the direction perpendicular to the adjusting part, before the square ring sleeve moves downwards, the tail end of the ad