The invention provides a drainage pipe installation construction method for kitchens or bathrooms. The method comprises the steps of adopting a loft blanket for marking a formwork, locating water stop joints, pouring concrete, installing the water stop joints and installing drainage pipes. By means of the method, the drainage pipes in the kitchens or the bathrooms which are located vertically on the same vertical plane and in the same building can be installed fast and accurately, the drainage stack joining deviation caused by positioning deviation of the pre-embedded water stop joints is avoided, the insertion bearing depths of the drainage pipes are marked through identification lines and identification circles, pipeline installation is tight, no leakage occurs, in the process of installation, visualized management over the insertion bearing depths is conducted effectively, it is avoided that under construction, the insertion bearing depth insufficiency cannot be detected, so that the insertion bearing depths of pipeline joints are insufficient, and water seeping or leakage is caused, the installation efficiency is high, and the labor and time are saved.