Abstract: Aiming at the technical idea of catalytic filter bag for synergistic purification of waste incineration flue gas deacidification, denitration and dedust, a synergistic purification experimental system was established. The effects of key factors on the denitration performance of catalytic filter bag were studied under the premise of waste incineration flue gas deacidification. Then the optimized parameters were selected to carry out the synergistic purification experiments. The results show that the denitration efficiency changes by about 15% within the applicable temperature range of 180−220 ℃. The ammonia escape decreases by about 0.9 μL/L for every 10 ℃ increase. At 150 ℃, both denitration efficiency and ammonia escape concentration deviate seriously from the demand value. With the increase of ammonia nitrogen ratio 0.1 mol/mol, flue gas moisture content 5%, inlet NO_x concentration 100 mg/m³ and filtration velocity 0.1 m/min, the variation of denitration efficiency is about 4.1%, −2.6%, 2.7% and −1.7% respectively, and the variation of ammonia escape concentration is about 1.9, 0.5, 2.3 and 0.6 μL/L respectively. In the synergistic purification experiments of deacidification and denitration, when the stoichiometric ratio of NaHCO₃ to HCl+SO₂ was 1.1 mol/mol, the removal efficiency of HCl was basically stable at about 96%, and the removal efficiency of SO₂ reached more than 97% and increased slightly with the increase of NH₃/NO. When the NH₃/NO is above 1 mol/mol, the denitration efficiency can reach more than 70%. For every 0.1 mol/mol increase in NH₃/NO, the denitration efficiency increases by about 3.2%, and the ammonia escape concentration increases by about 3.1 μL/L.