Movable lining strip for on-site square tube splicing and use method thereof

The invention relates to a movable lining strip for on-site square tube splicing and a using method thereof, and belongs to the technical field of steel constructions.The movable lining strip comprises a lower lining strip tube, an upper lining strip tube is arranged at the upper end of the lower lining strip tube, and a steel lining tube nested with the upper lining strip tube is arranged on the lower portion of the upper lining strip tube; the lower portion of the steel lining pipe is movably connected and fixed with the lower lining strip pipe in an inserted and embedded mode, long kidney-shaped round holes are formed in the front end or the front end and the rear end of the upper lining strip pipe, and shifting rods penetrating through the long kidney-shaped round holes are arranged at the front end or the front end and the rear end of the steel lining pipe. The device has the advantages of simple structure, convenience in operation and high mounting efficiency. The problems of elevation positioning and p