Abstract: The study on the aerodynamic characteristics of industrial boilers is of great significance to the normal operation of industrial boilers. The effect of the swirl intensity of secondary air and the outlet angles of primary air and secondary air on the flow field were investigated by particle image velocimetry (PIV) technique. The results indicate that the central recirculation region initially enlarges and then reduces with the increase of the outlet angle of primary air and enlarges gradually with the increase of the outlet angle of secondary air and its swirl intensity; the jet boundary decreases with the increase of the outlet angle of primary air and increases with the increase of the outlet angle of secondary air and its swirl intensity. The results provide reference for the design and operation of industrial boilers and burners.