With technology computer-aided design(TCAD)simulation software,we design a new structure of gallium oxide on gallium-nitride Schottky barrier diode(SBD).The parameters of gallium oxide are defined as new material parameters in the material library,and the SBD turn-on and breakdown behavior are simulated.The simulation results reveal that this new structure has a larger turn-on current than Ga2O3 SBD and a larger breakdown voltage than GaN SBD.Also,to solve the lattice mismatch problem in the real epitaxy,we add a ZnO layer as a transition layer.The simulations show that the device still has good properties after adding this layer.