The invention relates to a method for preparing a porous NiCo2O4/MnO2 nuclear shell nanowire array supercapacitor electrode material. The method includes the steps of placing nickel foam into a hydrochloric acid solution, carrying out ultrasonic cleaning to obtain cleaned nickel foam, dissolving Ni(NO3)2 6H2O, Co(NO3)2 6H2O and urea into water, carrying out stirring, placing the cleaned nickel foam into the mixture, carrying out the hydrothermal reaction for 3-18 hours at the temperature ranging from 90 DEG C to 180 DEG C, cooling the mixture till the mixture is at the indoor temperature, carrying out ultrasonic washing, drying, roasting, obtaining porous NiCo2O4 nanowire arrays, placing the porous NiCo2O4 nanowire arrays into a mixed solution of Mn(CH3COO)2 and CH3COONH4, carrying out electrochemical deposition and washing, drying, roasting, and obtaining the porous NiCo2O4/MnO2 nuclear shell nanowire array supercapacitor electrode material. The method is simple, environmentally friendly and low in cost, and the prepared porous NiCo2O4 nanowire arrays have the good electrochemical stability and are the excellent supercapacitor electrode material.