Abstract: Wet removal of NO from coal-fired flue gas by UV/H₂O₂ advanced oxidation process was investigated in a self-designed UV-bubble reactor. Several main influencing factors including UV intensity, H₂O₂ initial concentration, NO initial concentration and flue gas total flow on the removal efficiencies of NO were studied. The results show that the NO removal efficiency increases with increasing UV light intensity and H₂O₂ initial concentration. When they reach a certain value, the growth rate of the NO removal efficiency begins to become smaller. In addition, the NO removal efficiency approximately linearly decreases with the increase of the NO initial concentration and the total flow of flue gas. Based on the qualitative and quantitative detection of related ions in solution by ion chromatography (IC) and the mass balance of nitrogen element in NO, the removal paths of NO by UV/H₂O₂ process was discussed in depth.