The invention, which belongs to the technical field of prefabricated building, particularly relates to a double-door bathroom module with detachable corner columns for a prefabricated steel structurebuilding. The double-door bathroom module comprises a prefabricated steel structure building module, a thermal-insulation decorative integrated plate arranged at the side of the prefabricated steel structure building module, and a sanitary ware part arranged at the lower end surface of the prefabricated steel structure building module. A window and a door are installed at the thermal-insulation decorative integrated plate. According to the double-door bathroom module, splicing of a top frame, a bottom frame, and support columns is realized by detachable corner columns, so that the convenienceof the independent module dismounting is realized. Moreover, only the top frame and the bottom frame are assembled to realize factory manufacturing and no large assembling device and bed jig are needed, so that the actual production efficiency of the factory is improved, the production cost is saved, and the long-distance transportation and installation of the steel structure modules are realized.