Abstract: Numerical simulation and analysis were carried out on two-phase flow field in a new type gas-outside liquid-inside atomizer by computational fluid dynamics (CFD) technique, during which the influence of inlet gas/liquid pressure on the two-phase flow was studied, while the simulation results verified with experimental data. Results show that the outlet turbulence intensity of nozzle increases with the rise of inlet gas/liquid pressure in the range of 0.1—0.5MPa. Raising the inlet gas and inlet liquid pressure is respectively favorable to the reduction and uniformity of particle sizes.