Various field experiments were conducted in order to measure the performance of air-assisted spraying system on super-high clearance sprayer. The effects of spray pressure and speed of sprayer, air flow rate of air curtain and plant canopy characteristics on droplet distribution, deposition uniformity and droplet drift were studied. The experiment results indicated that droplet drift could reduce obviously with air-assisted spraying system. It also showed that air flow rate of air-assisted was the determinant factor, and the penetrability and deposition of droplets had positive correlation. Plant canopy characteristics had significant effect on droplet deposition. The deposit rate increased and the effect of deposition improved with the same sprayer speed when the spray pressure increased. However, it has no obvious effect on penetration of droplet. The speed of sprayer had no obvious effect on the droplet deposition.