Abstract: Due to the traditional non-catalytic reduction denitrification (SNCR) technology using urea or ammonia as reducing agents has problems such as decomposition of the reducing agent is insufficient, reaction temperature is high, and denitrification efficiency is low, solid denitrification agent can be used to overcome the above problems. A solid polymeric denitrifier was prepared with melamine, urea and formaldehyde as matrix. And the effects of reaction temperature, O₂ volume fraction, H₂O volume fraction, residence time and ammonia-nitrogen ratio on reaction activity were analyzed. Results show that the active temperature window of solid polymer denitration agent is lower than that of conventional reducing agent. When the volume fraction of O₂ is 1.2%, the denitrification efficiency reaches the highest by 84.2%, and when the volume fraction of H₂O is 1.4%, the denitrification efficiency reaches the highest by 91.4%. However, the effect of residence time on the reactivity activity of denitrification agent is not obvious. While the effect of ammonia nitrogen ratio is more obvious. When the ammonia-nitrogen ratio is 1.5, the denitrification efficiency is the highest.