Abstract: Aiming at solving the problems of high atomization pressure and small atomization range in the development of current atomization nozzles, a new atomization nozzle was designed, and its atomization characteristics were analyzed. A laser particle size tester was used to investigate the effects of pressure（0.15-0.30 MPa） and different outlet diameters（0.3-0.9 mm） on the nozzle atomization cone angle, velocity field, and droplet size, to obtain the changed rules of flow characteristics of the flow field under different test conditions. It is found that under low pressure, the atomization cone angle is greatly affected by the nozzle outlet diameter, and the larger the outlet contraction angle, the better the atomization characteristics. The nozzle with a outlet diameter of 0.9 mm can achieve a relatively wide range of operation when the length-to-diameter ratio of spray cavity is 1 and the outlet contraction angle is 75°. With the increase of working pressure, the maximum value of droplet velocity also increases significantly, but the pressure has little influence on the overall velocity distribution of the atomization flow field. The droplet diameter also increases with the increase of outlet diameter, and the nozzle outlet diameter has a significant impact on the droplet diameter, but the larger the outlet diameter, the smaller the droplet velocity under the same droplet diameter. This result provides a reference for the application of nozzles in the medium and low pressure range.