The construction of urban sewage treatment plants should avoid residential areas and choose low-lying areas with good power conditions, which are located in the lower reaches of the city and conform to the principle of sewage treatment plant location. It is also called sewage treatment plant or sewage plant in the city. It is often called a processing station located in a factory. When sewage enters the urban drainage pipeline, the treatment station is actually a pretreatment facility. Sewage treatment plant is a complex system composed of multiple unit processes. The cost and efficiency of each unit process are interrelated and influenced each other, which ultimately determines the cost and efficiency of the whole system.