With the continuous increase of urban domestic sewage and production wastewater discharge, the odour treatment has been enhanced in the sewage treatment process. At present, the odour problem of wastewater treatment plant should be treated jointly by various technologies. In this paper, the biological process and oxidation process were mainly selected to study the odour treatment in wastewater treatment plants, and two sets of pilot equipment in biological process and oxidation process respectively were established for pilot test. The test results showed that the biological process has a very good effect on treating the odour in the sewage tanks, and the treatment effect of N2 and H2S is relatively stable; the “alkali absorption + oxidation” method produces a stable effect on treating the odour gas produced by other adjusting tanks. At pH of 7.5-9, the potential of 700-850, and the liquid-gas ratio between 4.7L/m3-6.0L/m3, the best treatment effect can be achieved on the H2S.