Abstract: Based on the problems of energy crisis and environmental pollution, it is very important to develop new high-performance energy storage devices. Supercapacitors are favored by researchers because of their high specific energy and good stability. Biomass carbon is obtained by pre-carbonization and activation of biomass materials, with developed pore size, high active specific surface area, and rich resources, which has good application prospects as a supercapacitor material. In order to meet the high specific capacity and high cycle stability of supercapacitors, the current effective method is to combine biomass carbon materials with pseudo capacitor materials. Transition metal oxide MnO₂ has become the most promising pseudocapacitor material due to its high theoretical specific capacitance, wide potential window, low cost and environmental friendliness. The research shows that the specific capacitance and energy density of the supercapacitor made of the composite material of biomass carbon and transition metal oxide are significantly improved. This paper mainly introduces the source, characteristics and preparation methods of biomass carbon, also introduces the composite methods of biomass carbon and MnO₂ and the research progress of biomass carbon@MnO₂ composite materials, and finally looks forward to the development trend of biomass carbon@MnO₂ based supercapacitors.