The invention provides an NiO/Ni catalyst and a preparation method and application thereof. Oxidized NiO and reduced Ni of foam Ni adhere to foam Ni through a linear sweep voltammetry and a linear cyclic voltammetry, the NiO/Ni catalyst is formed, and the NiO/Ni catalyst has good electrical conductivity in a three-electrode system and an alkaline solution condition and can effectively catalyze methane. According to the NiO/Ni catalyst and the preparation method and application thereof, under a constant potential, the NiO/Ni catalyst can be utilized to effectively electrocatalyse methane, catalytic oxidation products of methane are carbon monoxide, methyl alcohol and ethyl alcohol, and particularly, forming of ethyl alcohol has important economic value for utilization of methane.