Abstract: In order to study the influence of the nozzle arrangement on the effective spray width of the multi-rotor UAV wind field, the simulation and analysis of the wind field in the front, middle and rear propeller spray area of the multi-rotor UAV were carried out based on SolidWorks 2016 software. In this wind field, By changing the installation position of the nozzle, the influence of the rotor wind field on the effective spray width of the droplet was studied when the two propellers in front of the fuselage were rotated in different directions. The test results showed that when the two propellers in front of the fuselage were internal rotation, the flying speed was 4 m/s and the flying height was 2 m, the effective spray widths of the front and rear of the nozzle were 3 m and 2 m respectively; Compared with the two propellers in front of the fuselage, the total deposition density of the droplets was 26.8% and 66.7% higher, respectively, and the effective spray width was 1 m and 0.5 m respectively. This study can provide reference for the further study of drift and deposition of droplets under coupled wind field disturbance during flight operations.