Abstract： To solve the problem that the airflow field distribution of the orchard airblast sprayer with axial flow fan was difficult to match the spray requirement of the canopy area of fruit tree, a method was proposed for optimizing the airflow field of the fan. By adding and optimizing air deflectors inside the blower on the middle and rear airflow guide plate and the outlet of blower, the matching effect between the airflow field and the spray requirement of the canopy of fruit tree was enhanced to improve the spray quality. Applying SolidWorks, PolyWorks and Geomagic Studio, the threedimensional model of blower was established. Based on the κε turbulence model, the Fluent software was used to simulate the airflow field. The prototype was produced， and the actual airflow velocity was measured and compared. The results show that by optimizing the diversion device, the average airflow speeds on the left and right side of the sprayer are respectively increased by 291% and 325% in the height range from 100 to 190 cm of fruit tree canopy.The penetration ability of the airflow to the fruit tree canopy can be enhanced to improve the spray effect.
