“Gallium nitride devices have attracted much attention in the field of radiation resistance applications. Researchers conducted 5 MeV proton irradiation experiments on enhanced Cascoe cascade structure and P-GaN gate structure GaN high electron mobility transistor devices, analyzed the degradation law of device electrical characteristics, and clarified the damage mechanism of proton irradiation effect. The research results have certain reference value for the reinforcement design of GaN power devices and the selection of aerospace application devices.”