Abstract: Aiming at the problem of poor efficiency of traditional atomizing nozzles in collecting fine dust, the atomization performance and dust removal efficiency of supersonic siphon atomizing nozzle and inner mixed atomizing nozzle were compared and analyzed by using the self-built test system of spray characteristics and dust removal efficiency. The results show that the fog-drop size decreases with the increase of air supply pressure; the fog-drop size increases with the increase of nozzle exit distance; under the optimal atomization conditions, the atomizing particle size of supersonic siphon air atomizing nozzle is smaller and the droplets are evenly distributed; in the area of 30 cm to 60 cm from the nozzle, the larger the air supply pressure, the faster the fog-drop velocity, the smaller the fog-drop axial velocity attenuation degree; in the area of 60 cm to 90 cm from the nozzle, the larger the air supply pressure, the faster the fog-drop velocity, the greater the fog-drop axial velocity attenuation degree; under the optimal atomizing conditions, the dust removal efficiency of supersonic siphoning nozzle for total dust and respirable dust is as high as 91.46% and 90.77%. The dust removal efficiency of the internal-mix nozzle is only 80.31% and 75.22%. The supersonic siphon air atomizing nozzle has higher dust removal efficiency and better dust removal effect on total coal dust and respirable dust.