Marine vertical centrifugal pump

The invention relates to the technical field of centrifugal pumps, in particular to a marine vertical centrifugal pump which comprises a base and a cylinder body, the cylinder body is fixedly arranged on the base, a driving shaft is rotatably connected to a top plate of the cylinder body in a penetrating mode through a bearing, an impeller is arranged in the cylinder body, the impeller is fixedly arranged on the driving shaft, and a water inlet pipe is fixed to a bottom plate of the cylinder body in a penetrating mode. A water outlet pipe is fixed to a rear side plate of the cylinder body in a penetrating mode, the water suction mechanism is arranged on the base, the driving mechanism is arranged on the cylinder body, and the communicating vessel mechanism is arranged on the water inlet pipe in series. A piston type water pumping structure is arranged, an adjustable communication structure is arranged by means of a water inlet pipe structure of the centrifugal pump, and then water can be injected into a cylin