The spraying dedusting technique using equipment that is mounted outside a roadheader is an important dust prevention measure in fully-mechanized excavation faces. In this study, ANSYS-FLUENT software was used for investigating the atomizing properties and the related variation rules of the nozzles with different orifice diameters (1.6 mm, 2.0 mm, 2.4 mm) under different spraying pressures from 1 MPa to 5.5 MPa. The conclusions are as follows: the relationship between the mean droplet size and spraying pressure can be fitted as a power function, as the spraying pressure increased, the variation of the droplet size tended to be small, and the uniformity degrees of the droplet size distribution reached the optimum level at a spraying pressure of 5 MPa. Under a spraying pressure of 5 MPa, the number of droplets in the target area increased greatly when a nozzle with an orifice diameter of 2.4 mm, the formed spray field exhibited the greatest spray concentration, which can wrap the cutting head effectively and provide the best performance with regard to dust suppression. Therefore, the use of a nozzle with an orifice diameter of 2.4 mm can achieve an optimal dust suppression performance under a spraying pressure of 5 MPa. (C) 2019 Elsevier B.V. All rights reserved.