According to modern orchard planting pattern, a kind of self-propelled air-blowing orchard sprayer was developed. Adopting theoretical calculation and virtual prototype technology, the whole structure design and the key components technical parameters were determined. A ring fan was designed for modern orchard. The impeller was 0.7 m and outlet width was 0.13 m. The step-less transmission of fan was accomplished from 0 to 2000 r/min. The field experiment showed that the front deposition reached to 61.22% and other side reached to 20.90% inside the trees. In the surface of the trees, the front deposition reached to 77.22% and other side reached to 37.17%. The operation efficiency reached to 1.02 hm2/h. 