The invention discloses an prefabricated decoration suspended ceiling, and belongs to the technical field of suspended ceilings. The prefabricated decoration suspended ceiling comprises a first combined suspended ceiling plate, a second combined suspended ceiling plate, an oil box, an expansion sleeve, a connecting assembly, an assembling assembly, and an oil coating brush. According to the prefabricated decoration suspended ceiling, the assembling assembly is installed in the suspended ceiling and is composed of a assembling stud and a rotating sleeve; when the suspended ceiling plates are installed, the rotating sleeve is directly rotated, the rotating sleeve can automatically drive the assembling stud to move outwards and is directly connected with the interior of a threaded hole of a ceiling groove in the top of a building in a threaded mode, so that the rapid installation of the suspended ceiling plates is completed; meanwhile, a hidden design is adopted for the assembling assembly, so that the attractiveness of the whole suspended ceiling plates after installation is not affected; and meanwhile, the oil box is installed in top grooves formed in the side faces of the suspendedceiling plates, and the oil coating brush installed outside the oil box can make contact with the assembling stud in an attached mode, so that the lubricating degree of the assembling stud is effectively guaranteed, and when the assembly stud is rotated, the labor is saved, the operation is smooth, and the installation efficiency of the ceiling plates is ensured.