Centrifugal water pump

The invention discloses a centrifugal water pump. The centrifugal water pump comprises a pump body, a pump cavity is formed in the pump body, a pump cover is fixedly installed at an opening in the right end of the pump cavity, a power shaft is rotationally connected into the pump cover, and a first wheel disc is arranged at one end of the power shaft; a water inlet pipeline and a water outlet pipeline are arranged on the side surface of the pump body; a sliding groove is formed in the power shaft, a protruding shaft is connected into the sliding groove in a sliding mode, and a second wheel disc is arranged at the left end of the protruding shaft; a plurality of first blades are hinged to the first wheel disc; a plurality of second blades are hinged to the second wheel disc; the first blades and the second blades are hinged to each other; when the protruding shaft slides leftwards, the first blades and the second blades are unfolded, the displacement of the centrifugal water pump is increased, and when the pro