Abstract: Steam activated carbon (AC) was prepared by using coconut shell as raw material, followed by using hydrothermal method and ethanol and water as solvent to prepare capacitance super-capacitor (GAC1-GAC5) with the mass ratios of AC and graphene(GR) 90:0, 90:5, 90:54, 90:90 and 54:90. By nitrogen adsorption-desorption, XRD and SEM methods, the pore structure and surface morphology of activated carbon were characterized. Comparison of different composite capacitance ratio super-capacitor electrode material was analyzed by cyclic voltammetry(CV), galvanostatic charge-discharge(GCD) method. The experimental results showed that the specific surface area of coconut shell activated carbon was 2 482 m²/g, and its pore diameter was mainly distributed at 2-4 nm, with the pore volume as 1.33 cm³/g, specific capacitance was 85 F/g in 6 mol/L KOH electrolyte. Under the conditions of carbonization temperature of 800℃, activation temperature of 900℃ and activation time of 1.5 h, the addition of the graphite improved the composite material capacitance up to 186 F/g.