The invention discloses a medium/metal/medium nanostructure membrane. The membrane comprises a substrate, a first medium layer, a metal layer and a second medium layer, wherein the first medium layer, the metal layer and the second medium layer are arranged on the substrate in turn; the substrate is a mono-crystalline silicon slice, a mono-crystalline sapphire slice or a quartz glass sheet; the first medium layer and the second medium layer are simultaneously indium oxide layers or zinc oxide layers of which the thicknesses are between 20 and 100 nanometers; the metal layer is a silver layer,a gold layer or an aluminum layer of which the thickness is between 5 and 40 nanometers; and the nanostructure membrane can be prepared by an electron beam evaporation method or a method for combining magnetron sputtering with thermal evaporation. Compared with a metal/medium double-layer structure membrane, the medium/metal/medium nanostructure membrane of the invention has the advantages of high luminescence enhancement factor, long service life and wide development prospect.