The invention discloses a preparation method and an application of a nanowire-like nickel-based complex electrode material. The preparation method comprises the specific steps of mixing bivalent inorganic nickel salt, nitrilotriacetic acid, deionized water and isopropanol; carrying out full stirring; and transferring a mixture into a reaction kettle for reaction to obtain the nanowire-like nickel-based complex electrode material with a one-dimensional nanowire structure. Under hydrothermal conditions, the nitrilotriacetic acid and nickel ions adsorbed on the surface of the nitrilotriacetic acid are coordinated to form a one-dimensional nanowire-like nickel-based complex; and the nanowire-like nickel-based complex electrode material prepared with the method is uniform in property and singlein morphology, can enlarge the effective contact area and shorten the electron transmission distance, is applied to a supercapacitor electrode material, and shows relatively high specific capacitanceand rate performance.