Abstract: In order to study on ammonia emission characteristics of sewage treatment process of a pharmaceutical enterprise, waste gas samples were collected from several wastewater treatment units and waste gas discharge outlet in sewage treatment progress of pharmaceutical industry to analyze NH₃ emission characteristics. The study results showed that:the maximum NH₃ emission appeared at hydrolysis acidification unite, the point concentration reached 62.89 mg∕m ³,emission reached 3 360 mg∕m ³ for each treatment of 1 m ³ sewage, The sewage treatment process of each unit of ammonia amount was 0.97 kg∕h, the conversion for each treatment 1 m ³wastewater, ammonia production 9 312 mg∕m ³, after the treatment of waste gas discharged into the environment ammonia was 0.25 kg∕h, emission reached 2 400 mg∕m ³ for each treatment of 1 m ³ sewage, ammonia removal rate was 74.2%, the emission of ammonia gas was obviously reduced after the treatment of exhaust gas. Waste gas treatment in the southern and northern areas adopts the technology of caustic wash+oxidation+washing. The removal rate of ammonia was 93.3% and 83.1%, The ammonia removal rate of the waste gas treatment facility in the biological zone is 39.1%. Caustic wash+oxidation+washing has better effect than biotrickling filter in the removal the ammonia.