Abstract: A high-brightness flat lamp structure comprises a reflecting plate, a plurality of UV light sources, a macromolecular polymer layer and a fluorescent powder layer. The UV light sources and the macromolecular polymer layer are sandwiched between the reflecting plate and the fluorescent powder layer. The functions of diffusing and guiding light of the macromolecular polymer layer are exploited to let UV lights emitted by the UV light sources and reflected by the reflecting plate excite the fluorescent powder layer to radiate high-brightness visible lights. Besides, macromolecular polymer and fluorescent powder can be mixed up to form a mixed layer of macromolecular polymer and fluorescent powder to let UV lights emitted by the UV light sources and reflected by the reflecting plate directly excite fluorescent powder to radiate high-brightness visible lights.