The treatment of domestic sewage is an environmental protection measure that needs everyone's attention. What kind of measures should we take when we treat domestic sewage? What is the mode of operation? What kind of domestic sewage treatment equipment should we choose? As the core of domestic sewage treatment is the biochemical part, so we call the sewage treatment process refers to this part, such as contact oxidation, SBR, a / O, etc. . In a wastewater treatment process using biochemical processes including anaerobic and aerobic treatment of domestic wastewater, according to the quantity, quality and site conditions of domestic sewage, the choice of different sewage treatment process has a decisive impact on investment and operation cost. For many years, the secondary biological treatment of domestic sewage in cities mostly uses activated sludge, which is a secondary biological treatment process applied in the world at present, and has the advantages of high treatment capacity and good effluent quality. At present, in the field of research and application of municipal domestic sewage treatment, the common problems are as follows: 1 using the traditional activated sludge, the capital cost and operation cost are often high, the energy consumption is large, the management is complex, the sludge bulking is easy to occur; 2 with the increasingly strict wastewater discharge standard, the demand for nitrogen, phosphorus and other nutrients in wastewater is higher, and the traditional wastewater treatment process with the function of nitrogen and phosphorus removal is mainly activated sludge, many anaerobic and aerobic reaction pools are often connected in series to form multi-stage reaction pools, and the purpose of nitrogen and phosphorus removal can be achieved by increasing internal circulation. 3 at present, the treatment of urban sewage is mainly concentrated treatment, the investment of huge sewage collection system far exceeds the investment of the Sewage Treatment itself, so the construction of large-scale Sewage Treatment, centralized treatment of domestic sewage. Many places began to use domestic sewage treatment equipment, sewage has a good treatment. By adopting proper sewage treatment equipment, we can effectively treat our sewage, make our ecological environment sustainable, and provide us with a safe and healthy living environment.