Sewage Treatment Plant in Hefei Economic&Technological Development Zone was commenced in 2016, and andvanced water treatment technology, oxidation ditch, is adopted. Construction sacle is 100000m3/d, and effluent quality reaches category-IV water standard, which is ahead of similar indicators of domestic sewage treatment plants. The project can effectively mitigate the pollution to water environment in southwest Hefei and downstream water body, and can significantly improve water quality.