The invention discloses a high-breakdown-voltage gallium-oxide Schottky diode structure comprising a highly-doped n type Ga2O3 substrate (1), a lowly-doped n type Ga2O3 epitaxial layer (2), and an anode electrode (4). A cathode electrode (5) is deposited at the lower surface of the substrate; the anode electrode and the epitaxial layer (2) are in Schottky contact; and the cathode electrode and the substrate (1) are in ohmic contact. An organic ferroelectric dielectric layer (3) with a thickness of 300 to 500 nm is deposited on the upper surface of the epitaxial layer (2). A circular hole is etched in the organic ferroelectric dielectric layer; the anode electrode is deposited in the hole of the organic ferroelectric dielectric layer; a field plate (6) is deposited at the edge of the hole; and the field is arranged on the organic ferroelectric dielectric layer and is connected with the anode electrode. Therefore, the reverse breakdown voltage can be improved and the forward characteristic is not changed. The high-breakdown-voltage gallium-oxide Schottky diode can be applied to a high-speed integration circuit and a microwave circuit.