Abstract: To study the atomization effect of plant protection spray nozzle, based on the Lagrangian particle tracking gas-liquid two-phase flow model in CFD, and combined with the Pressure-swirl-atomize, and the Air-blast atomizer, respectively, the distribution of droplet size, movement velocity and mass concentration distribution under different wind speeds were calculated and compared. The calculation results show that in the pressure atomization model, the particle size of fog drops less than 100 μm accounts for less than 2%, and the particle size of fine fog drops 175 μm accounts for about 25%. The droplet velocity near the spray nozzle is higher, which is about 5 times that of the air atomization model. The droplet mass concentration distribution is more uniform. When the wind speed reaches 4 m/s, the distribution ratio of fine fog drops increases, and secondary fragmentation occurs, the droplets will burst again. In the air atomization model, the particle size of medium droplets is 400-600 μm, and the proportion accounts for about 20%. The droplet velocity decays slowly, and the droplet is not easy to move against wind near the spray nozzle. The deposition range of fog droplets is small and the spray amplitude is narrow. Most of the fog droplets settle in the 1.5 m range centered on the nozzle. Furthermore, the low-speed wind tunnel test is completed to collect the droplet deposition and the chi-square test are both carried out. The test results show that the two atomization models are both reliable for droplet deposition in the spray field, but the deviation between the calculated value of the Pressure-swirl-atomize and the test value is smaller.