Centrifugal pump capable of being freely built and disassembled

A centrifugal pump capable of being freely built and detached comprises a motor and a pump body and further comprises a protective shell, a partition plate is arranged on one bottom face of the protective shell, a rotating shaft assembly connected with the motor is arranged in the protective shell, one end of the rotating shaft assembly penetrates through the partition plate and is arranged outside the protective shell, and the other end of the rotating shaft assembly is connected with the pump body. A plurality of first protruding blocks are arranged on the circumferential side face, close to the output shaft, of the motor, a plurality of second protruding blocks and a plurality of third protruding blocks are arranged on the circumferential side faces of the two ends of the protective shell respectively, the third protruding blocks are close to the partition plate, a plurality of fourth protruding blocks are arranged on the pump body, any first protruding block is connected with one second protruding block t