Abstract: To promote the utilization of renewable energy, it is necessary to develop efficient energy storage devices. Using waste grapefruit peel as carbon and nitrogen sources, N atom self-doped biomass-derived porous carbon materials were prepared through hydrothermal treatment and activation process, and the effects of different activators on the structure, elemental composition, micromorphology and electrochemical performance of carbon materials were studied. The results show that SPC-800 activated by KOH exhibits a specific surface area up to 1174.39 m²/g, showing the outstanding capacitive performance. The specific capacitance is 175.4 F/g at a current density of 1 A/g. After 5000 charge and discharge cycles (10 A/g), the capacitance retention rate is as high as 96%, showing excellent cycle stability. This study provides novel ideas for the resource utilization of agricultural waste and has reference value for the application and development of biomass-derived carbon-based materials in high-performance supercapacitor electrode materials.