Centrifugal pump

The invention relates to the technical field of centrifugal pumps, and discloses a centrifugal pump which comprises a casing, a casing cover, an impeller and a main shaft. A casing ring comprises a matching section, a positioning flange part and a protective flange part, and the positioning flange part and the protective flange part are perpendicularly arranged at the two ends of the matching section respectively and located on the different sides of the matching section. In order to prevent the spraying liquid from scouring the inner wall of the casing for a long time, the casing ring comprises the matching section, the positioning flange part and the protective flange part, the positioning flange part is used for being connected with the casing, the assembling section is used for being assembled with an impeller ring, and the protective flange part is perpendicular to the assembling section. Therefore, after the casing ring is installed, flushing liquid coming out of the assembling face is directly sprayed