Abstract: In order to study the spray characteristics and dust removal properties of internal-mixing air atomizing noz- zle,based on the experimental platform designed by authors for spray and dust removal,the dust removal efficiencies and spray performance parameters of the internal-mixing air atomizing nozzle and the X-type swirl pressure nozzle were measured. The spray performance parameters measured in the experiment include flow rate,droplet size,droplet volume concentration,spray angle and droplet velocity. The study results indicate that the water flow rate of air atomizing noz- zle appears exponential growth with the increase of water supply pressure,and the air flow rate decreases in the way of exponential. The air-liquid mass flow ration (ALR) decreases with the increase of water supply pressure. For the pres- sure nozzle,the water flow rate increases with the increase of the water supply pressure,and the water flow rate is pro- portional to the square root of water pressure. With the increase of water supply pressure,the spray range,droplet vol- ume concentration and droplet velocity of two kinds of nozzle all increase. The atomization angle of swirl pressure noz- zle is significantly larger than that of air atomizing nozzle,which has wider coverage. As the water supply pressure in- creases,the atomization angle of atomizing nozzle increases first and then decreases,and it decreases continuously at a modest pace for the X-type swirl pressure nozzle. With the help of compressed air,the atomizing nozzle can acquire the ideal droplet size under low water pressure,and the droplet size increases with the increase of the water supply pres- sure. For the pressure nozzle,the droplet size shows a change rule of decreasing with the further increase of the water supply pressure,only when the water pressure is high can reach the appropriate droplet size. Under the same water pressure,the droplet size and water flow rate of air atomizing nozzle are both less than those of pressure nozzle,but the droplet volume concentration,droplet velocity and dust removal efficiency are all higher than those of pressure nozzle. Compared with the pressure spray,the air-water spray has a significant advantage. For the same dust removal efficien- cy,the water consumption of air-water spray is merely half of those of pressure spray.