Transparency adjustment unit and display device

The invention discloses a transparency adjustment unit and a display device. The transparency adjustment unit comprises a reduction electrode, a metal ion layer, a selective permeable membrane and a first transparent electrode, wherein the reduction electrode comprises a metal; the metal ion layer is located at one side of the reduction electrode; the selective permeable membrane is located at one side, departing from the reduction electrode, of the metal ion layer; the first transparent electrode is located at one side, departing from the reduction electrode, of the selective permeable membrane; when positive voltage is applied to the reduction electrode and negative voltage is added to the first transparent electrode, the metal of the reduction electrode is oxidized into metal ions, the metal ions enter the metal ion layer and the light transmittance is improved due to reduction of the thickness of the metal in the reduction electrode; and when the negative voltage is added to the reduction electrode and the positive voltage is applied to the first transparent electrode, the metal ions in the metal ion layer are reduced into the metal, the metal is deposited on the reduction electrode and the light transmittance is improved due to increase of the thickness of the metal in the reduction electrode.