Wastewater treatment plants (WWTPs) produce malodorous gas, mainly NH3 and H2S, which adversely affect human senses and health. This study examined the malodorous gas treatment technologies of existing WWTPs, with engineering examples, comparative analysis of the removal efficiency of NH3, H2S and odor by biological filter, pulsed plasma discharge technology and the combination technologies of biological filter + pulsed plasma discharge based on actual test data. The results showed that the average removal rates of odor, NH3 and H2S after treatment by the biological filter were 52.0%, 63.9%, and 86.6%, respectively; after treatment by pulsed plasma discharge technique, the average removal of odor, NH3 and H2S were 71.1%, 45.4% and 69.9%, respectively; after treatment by the combined biological filter and pulsed plasma discharge technique, the average removal of odor, NH3 and H2S were 81.7%, 75.5% and 91.9%, respectively. At the same time, the outlet concentrations all met the emission standards for malodorous pollutants.