Abstract: According to the reinjection sewage treatment situation in Shengli Oilfield, the oilfield sewage treatment technology progress was introduced. Aiming at the characteristics of sewage treatment in Shengli Oilfield, the tests and application of three kinds of technology were introduced: ①the secondary level nitrogen flotation technology improved the oil removal effect and reduced the corrosion of the pipe network and equipment; ②aiming at the reinjection sewage of strong corrosion, the electrochemical preoxidation technology was implemented, and its implementation was introduced in detail; ③aiming at the water reinjection produced from chemical flooding, the high gradient coalescence flotation technology was studied and tested. The high gradient coalescence flotation field test was introduced in detail. The future development of oilfield sewage treatment technology was prospected finally.