Abstract: In order to investigate the effect of microwave heating on activated carbon and its electrochemical performance， hypercoals-based activated carbon(HAC) was prepared from hypercoal(HPC)by KOH activation under microwave heating. HAC was characterized by low temperature nitrogen adsorption, scanning eletron microscope, Fourier Transform Infrared Spectra and X-ray diffraction, the effects of activation temperature, activation time and the ratio of KOH to HPC on HAC and its electrochemical performance were investigated. The results showed that HAC could be prepared under the condition of the microwave irradiation power was 2 000 W, activation temperature was 600 ℃, activation time was 6 min and the ratio of KOH to HPC was 1.5, and the specific surface area could reach 1 035 m2/g and mesoporous percent was 38%. The specific capacitance and energy density of HAC electrode reached 277 F/g and 25.1 Wh/kg in three mol/L KOH electrolyte, it was proved that microwave heating was a low cost method for rapid preparation of activated carbon, and it also opened up a new way for the preparation and use of HAC.