Biogas was suggested more suitable as reburning fuel to reduce NO emission and Miller-Bowan’s mechanism was performed to analyze the effect of reaction environment in the process of biogas reburning. Results show that the NO reduction efficiency increased with the increase of hydrocarbon in biogas, reburning fuel ratio, initial NO concentration and residence time. When initial NO concentration reached 700 l/l or residence time reaches 2 s, the dependence on initial NO concentration weakened greatly. NO reduction reached maximum at 1200 – 1400 K and enhanced abruptly at the stoichiometric ratio of 0.85 with the decrease of stoichiometirc ratio. The investigations indicated the optimal biogas
reburnning technology potential to reduce NO pollution.