The invention discloses a preparation method of a polyaniline/nickel hydroxide supercapacitor composite electrode material. An aniline monomer is added into a nickel ion water solution, and stirred atthe room temperature until the aniline is fully dissolved to obtain a uniform mixed solution to be used as an electrolyte; next, compaction carbon paper or graphene paper is used as a working electrode and a counter electrode at the same time, and a saturated calomel electrode is used as a reference electrode to assemble a three-electrode system; cyclic voltammetry scanning at the scanning rate of 5-2,000mV/s and the voltage window of minus 1V to 1V is performed for 100-10,000 cycles; next, the working electrode and the counter electrode are taken off and immersed by deionized water over night to remove impurity ions; and finally, the product is dried at a temperature of 60 DEG C for 24h to obtain the polyaniline/nickel hydroxide supercapacitor composite electrode material. The method hasa simple, environment friendly and reliable preparation process, wide raw material resource and low cost, and is suitable for industrial production; and the obtained electrode material has high conductivity and high electrical capacity, and is an ideal supercapacitor electrode material.