The circulating water pump is widely used in various occasions which require providing cooling medium circularly. Typically for example, the circulating water pump used for steam turbine, the circulating water pump used for automobile and for large-scale air conditioning unit and so on. There are large-scale, small-scale and minitype circulating water pumps, which can be selected according to specific occasion. The submerged circulating water pump is used to transport the raw water and the sludge from the sewage treatment plant, flood-drainage and irrigation. It has high efficient stainless steel propeller and is completely submerged in installation; it is provided with built-in protection for motor(the installation is flexible) and with the control and protection system.