Convenient drainage system of axial flow pump

A middle base is installed on the middle layer of an axial flow pump shell and comprises a bottom plate, the inner edge of the bottom plate is fixed around a pump shaft of the axial flow pump, the outer edge of the bottom plate is fixed to the axial flow pump shell, the outer edge of the bottom plate is bent upwards to be provided with an outer baffle, and reinforcing rib plates are arranged at the upper end of the bottom plate and the inner side of the outer baffle in a protruding mode. A water collecting pit is arranged on one side of the bottom plate, a water level alarm instrument is arranged in the water collecting pit, the outer baffle is provided with a pump support, the pump support is fixedly provided with a self-sucking pump, the water level alarm instrument and the self-sucking pump are electrically connected with an integrated controller, the self-sucking pump and a filler component on the outer side of a pump shaft are communicated with the water collecting pit through a pipeline, and a water out