The invention discloses a splicing steel pipe and a construction method of a splicing type pipe curtain structure supporting system using the same. The splicing steel pipe comprises a recyclable partand an arc part formed by rolling a steel plate, the cross section of the arc part is in a major arc shape, and the cross section of the recyclable part is in a minor arc shape. A plurality of throughholes are formed in the side wall of the arc part. Grooves are formed in two side walls of an opening of the recyclable part, two side walls of an opening of the arc part are arranged in the groovesrespectively, the arc part and the recyclable part are spliced to form the splicing steel pipe, and the cross section of the splicing steel pipe is in a circular ring shape. A mode of welding a plurality of arc parts is adopted, so that the defect that the transverse rigidity and the bearing capacity are relatively weak due to the fact that steel pipes of a traditional pipe curtain structure are connected only through locking openings is overcome. Meanwhile, the waterproof performance is very good, soil in the pipe is convenient to remove, and the construction efficiency is improved.