The invention relates to the technical field of waste gas treatment, specifically to a malodorous waste gas treatment device. The malodorous waste gas treatment device comprises a spraying unit and acatalytic reaction unit, wherein the spraying unit comprises a spraying reaction kettle and a circulating water pump arranged at the side of the spraying reaction kettle; the side wall of the centralpart of the spraying reaction kettle is provided with a gas inlet joint; the side wall of the upper end of the spraying reaction kettle is provided with a gas outlet joint; the spraying unit communicates with the catalytic reaction unit through a first connecting pipe; the spraying reaction kettle communicates with the circulating water pump through a second connecting pipe; and the catalytic reaction unit comprises a drying adsorption box, a catalytic oxidation box and an adsorption deodorizing box. According to the invention, spraying, drying adsorption, catalytic reaction and adsorption deodorizing to waste gas are successively performed through the spraying reaction kettle, the drying adsorption box, the catalytic oxidation box and the adsorption deodorizing box; harmful substances inmalodorous waste gas can be effectively neutralized; odor in odorous gas is eliminated through adsorption action or chemical reaction treatment with chemicals; and the malodorous waste gas treatment device has simple structure and strong practicability.