The invention belongs to the field of environmental protection, and particularly relates to an ozone catalytic oxidation wastewater treatment device and a treatment method thereof, wherein the treatment device comprises a water inlet system, a catalytic oxidation tower, a spray tower and an ozone treatment system, hydrogen peroxide is used for oxidation pretreatment of wastewater, and the load ofa subsequent treatment unit is reduced; residual ozone after catalytic oxidation is used for carrying out spraying treatment on the pretreated wastewater, so that the ozone utilization rate is increased; an ozone catalyst packing layer with excellent performance is arranged in the catalytic oxidation tower to catalyze ozone to generate a large number of hydroxyl radicals with strong oxidizing property, so that the oxidation capacity of the system is greatly enhanced, and the improvement of the reaction effect is promoted. The method has the advantages of high ozone utilization rate, low operation cost and good treatment effect, and has a good application prospect.