A centrifugal supercharger comprises a power input shaft, a large gear, a small gear shaft, a shaft sleeve, an impeller, an exhaust wheel, a bearing, a coupler, a volute casing and the like. The centrifugal supercharger is characterized in that the large gear is mounted on the power input shaft and is engaged with the small gear shaft through inclined teeth, and through an inclined gear, mechanical transmission will be more stable and safer; the impeller, the exhaust wheel, the shaft sleeve, a shaft head nut and other parts are mounted on the small gear shaft to form a main component of the centrifugal supercharger, and the main component is a rotor of the centrifugal supercharger; and the exhaust wheel is arranged on the outer side of a sealing device at the contact position of the impeller and the volute casing of the supercharger. A casting structure is adopted in a machine shell, and an X-shaped structural manner is adopted in an upper volute casing body and a lower volute casing body; a stainless steel closed type impeller is adopted as the impeller, a blade manner of a backward bending structure is adopted in blades, the blades are alternative in length, and the number of the blades is 11; and according to the centrifugal supercharger, the working efficiency is greatly improved, the manufacturing and maintaining cost is greatly reduced, the service life of the supercharger is greatly prolonged, and the centrifugal supercharger is unanimously praised.