Abstract: Fluent software was employed to simulate the combustion of pulverized coal under the O₂/CO₂, O₂/N₂ atmosphere. The ignition characteristics and NO_x emission characteristics of the two kinds of cases were compared. The influence of oxygen content on the combustion of pulverized coal with different particle sizes (18, 79 m) was simulated under O₂/CO₂ atmosphere, and the ignition distance of pulverized coal combustion was studied. The results show that when the oxygen content is the same, compared with O₂/N₂ atmosphere, the ignition distance of 18 μm pulverized coal (superfine pulverized coal) under O₂/CO₂ atmosphere is larger, and the ignition distance of 79 μm pulverized coal is smaller. Under O₂/CO₂ atmosphere, the ignition distance decreases with the increase of oxygen content. When the oxygen content is low, the ignition distance varies greatly with the oxygen content, and the precipitation and the peak value of NO decrease with the increase of O₂ content in advance.