A splicing pipe for installing a door or window includes a first frame profile, a second frame profile, a heat insulation strip and at least two fasteners. A first clamping groove is formed on each of two sides of the first frame profile, and a second clamping groove is formed on each of two sides of the second frame profile. The first clamping groove and the second clamping groove are both used to connect to the door or window having glass. At least one of the first frame profile and the second frame profile on the same side is provided with an installation groove, and the fastener is inserted into the installation groove. The splicing pipe provided has the advantages of simple splicing operation and easy implementation, which can not only improve the splicing speed, but also guarantee the performance of the doors or windows after being spliced.