The invention discloses a monocrystal semiconductor oxide anode and electrolytic cell for preparing hydrogen peroxide. The anode comprises a semiconductor oxide layer and a substrate bearing the semiconductor oxide layer, wherein the semiconductor oxide layer is a pure-phase or bismuth vanadate-doped monocrystal wafer with crystal orientation of {111}, {110}, {100} or {010}. The substrate is conductive glass; and the semiconductor oxide layer covers a conductive film of the conductive glass. The anode is arranged on the cell wall of the electrolytic cell; and alkaline electrolyte is arranged in the electrolytic cell. Bias voltage is externally applied to the electrode of the electrolytic cell, or bias voltage is externally applied under an illumination condition, and H2O2 can be generated in the anode area while H2 is generated in the cathode area.