Abstract: In order to control odorous VOCs air emission from wastewater treatment plant for coal liquefaction project,the sewage tanks with high concentration at each openingsuch asthe oil separator,floatation tank,coal gasification wastewater pretreantment tank,equalization tank,hydrolysis-acidification tank,Intermediate sedimentation tank were sealed. According to the conditions of each treatment tank,the FRP arched plateand framed structure membrane coverwere adopted. Thewastegaswas collected and transported with PRP ventilation pipeline,and treated through prewashing-biotrickling filter-granular activated carbon adsorption in sequenceand finally discharged through15 m high exhaust funnel. The results show that after treatment the offgas meets the design requirements and the national air pollutant emission standard.