Abstract: In order to explore the distribution law of diffusion and settlement of droplets, as well as the influencing factors and effects of it of long range air-assisted sprayer, improve the efficiency of spray dust removal, by means of laboratory test and numerical simulation, the distribution of droplet diffusion and settlement of long range air-assisted sprayer were measured and statistically analyzed under the conditions of different air supply, spray pressure and nozzle diffusion angle. The results show that, take the z axis of outlet as the axis of symmetry, the diffusion and sedimentation distribution of fog flow at the air outlet of the long range air-assisted sprayer shows a "∩" changing tendency, the fog flow weight is approximately symmetrical distribution; the amount of air supply and droplet settling rate in the direction of the outlet z axis of the settlement distance are in a positive direction; the spray droplets settling rate and spray pressure at the same position are positive changes; the distance between the nozzle diffusion angle and the spray droplets settling rate is reversed in the direction of the outlet z axis.