Abstract: There were lots of problems in ammonia distillation process,the handing capacity were small,the equipments were easy to jam,the temperature of wastewater for biochemical treatment system was high,gas phase ammonia content were low.Optimize the ammonia distillation in coking enterprise using chemical process simulation software.The results show that,when the sewage flow are 100 t / h,and the gas phase ammonia content are 40 percent,the most suitable steam consumption are 11 t / h and the reflux ratio is 2.25.Add ammonia still,surplus ammonia water trough,low temperature water cooler and new type sieve tray.After transformation,the handling capacity of ammonia distillation system is 100 t / h,waste ammonia water concentration is less than 50 mg / L,the gas phase ammonia content is more than 40 percent,the temperature of wastewater for biochemical treatment system ranges from 25 ℃ to 35 ℃.