Aiming at the problems that the traditional air-fed spraying system of sprayer is difficult to accurately control the air volume, resulting in serious drift phenomenon and low utilization rate of liquid medicine, a spraying system with axial fan and annular nozzle was designed. The size parameters of annular nozzle and the installation position of nozzle were determined by CFD fluid simulation, benchmarking test and flow field simulation in annular nozzle. Single-factor and multi-factor orthogonal experiments were designed to study the effects of fan port wind speed, fan nozzle type and nozzle installation inclination angle on spray effect, and then the best spray parameter combination was determined. The results showed that the annular nozzle should be set in the center of the outlet end face of the axial fan, and the three nozzles were evenly distributed on the annular nozzle at an angle of 120°. Under the pneumatic action of the fan, the peak value of fog droplet deposition was in the range of 0.5~1.5m from the fan port, and the working distance between the air spray device and the target fruit tree should not exceed 1.5m. The air force of the fan was helpful to refine the fog drops, but the outlet wind speed should not be greater than or equal to 8m/s. There was a significant correlation between the overall spray performance and the nozzle inclination （P<0.01), and the performance of the nozzle with 60° installation inclination was the best. The deposition density of droplets was increased first and then decreased with the increase of fan nozzle type, and the volume median diameter of droplets was increased with the increase of fan nozzle type. The optimal configuration parameters were fan speed of 6m/s, nozzle type of 02, and nozzle installation angle of 60°. Under this parameters combination, the total amount of droplet deposition was 5.08μL/cm2, which indicated that the optimized model was reliable.