In view of the existing problems in the treatment of nitrate tail gas, such as  increases of system resistance, reduction of nitrate production, part of the production equipment to the new working condition matching, and the mismatching of etc., the tail gas denitration comprehensive treatment project were carried out. Some technologies, such as timely ensuring reaction parameters, determining the change of resistance, replacing the big wind pressure transformation blower, parallel ling exhaust gas absorption tower and the gas heat exchanger, and changing the automatic control sets etc. were implemented, thereby in the short term restoring the nitrate production, achieving the safe operation and standardized discharging, making the tail gas treatment plant adapt the production system, realizing best combination of the environmental benefits and economic benefits, as well as providing the reference for subsequent resource recovery and second preheating of tail gas.