In this paper, the experimental study on the atomization characteristics of pressure swirl nozzle is carried out by means of laser particle size analyzer and high speed camera. The influence of different pressure and difference nozzle diameter on Sauter mean diameter (SMD)、and the atomization angle was analyzed. The results showed that the SMD and the spray angle can not only decrease with the increase of the spray pressure, but also decrease with the decrease of the nozzle aperture; at the same time, with the increase of the spray distance, the SMD increases firstly and then decreases, and finally tends to be stable; the axial velocity of spray particles increases with the increase of the spray pressure, but also decreases with the increase of the nozzle diameter and the distance.