Submersible sewage pump because of its simple installation, small footprint, easy maintenance, no noise, etc., are widely used in municipal engineering projects, factories, commercial, hospitals, hotels, residential areas and other sewage discharge. At present, submersible sewage pumps in China are mainly manufactured and manufactured by domestic manufacturers, and a small part of their products are imported from abroad. Market prospects are very broad. However, due to the reliability of submersible sewage pump needs to be strengthened, therefore, to improve the technical content of their products is the main direction for the development of manufacturers. Submersible sewage pump vertical layout, the pump and motor coaxial, so that the weight of the rotating parts and the impeller to withstand the direction of the same water pressure; Second, the submersible sewage pump is used in the liquid, the sewage medium containing impurities, Sludge and other substances; Third, the submersible sewage pump is a centrifugal pump in its operation, the power is always increased with the flow rate increases, when the flow exceeds the design flow and reaches a certain value, the motor will be overloaded burn. The above problems will affect the service life of the submersible sewage pump to varying degrees. For the submersible sewage pump problems, some domestic manufacturers to focus on the development of pump protection system: Automatic alarm or cut off the power supply in case of abnormal pump operation. Although this approach can play a certain effect, and this protection is necessary, but this is not the fundamental solution to the problem, we should also focus on improving the performance of the pump, the problem is fundamentally resolved. Submersible sewage pump problems to be solved in the future is to improve the reliability of use, can adapt to a variety of working environment, optimize its structural design, to further improve the performance of submersible sewage pump.