The invention relates to the technical field of building engineering, in particular to a metal ceiling with curved-surface decorating plates and a separated connecting piece, which comprises the curved-surface decorating plates and the separated connecting piece, wherein the curved-surface decorating plates connected on the connecting piece are fixedly arranged in a ceiling in a room through a connecting rod by the connecting piece, the connecting piece comprises a central fixing disc slice and connecting brackets, the center of the central fixing disc slice is provided with a through hole, the central fixing disc slice is fixed onto the connecting rod of the ceiling in the room through the through hole, the connecting brackets can be fixed on the flanges of a plurality of triangular decorating plates or polygonal decorating plates, and the connecting brackets are provided with through holes which are fixed with through holes uniformly distributed at the periphery of the central fixing disc slice through bolts. In the invention, the decorating plates are not mutually contacted, so that the transversal extrusion between the adjacent decorating plates, caused by the dimension errors, can be overcome; the decorating plates can be conveniently assembled and disassembled, and each decorating plate can be independently assembled disassembled; and structurally, the decorating plates have enough bending degree, smoothness and rigidity, and simultaneously, the overhaul as well as the disassembly and the assembly are convenient.