Abstract: In order to understanding the importance of mechanism of dust control by spraying, the paper studied the wake flow field of jet droplet, and the impact of wake flow on dust particle’s sedimentation. Using Fluent software, the paper simulated the flow field around a static droplet, and got the velocity distribution of wake flow field of jet droplet by Galileo coordinate conversion theory, and got the average air velocity of dust particle in the windward. Through force analysis, it is known that dust particle’s drag force which dominates dust particle motion, so the relationship between the average air velocity of dust particle in the windward and dust particle’s drag force is established. This study shows that, the leeward side of jet droplet is a inhomogeneous wake flow, and the flow separation happens, the symmetry of jet droplet’s streamline in the windward and leeward disappears. In dust control by spraying, the wake effect of jet droplet plays the alternative role on dust particle's sedimentation, and the effect and influence of relation is d/D>s/D>Re_D.