Abstract: In this paper, the atomization characteristics of a dual-orifice pressure swirl atomizer were tested to address the low emissionlow-emission combustion problem in a certain specific type of aircraft engine combustor. RP-3 aviation kerosene was used as fuel. High-speed photography was used to shoot the spray form under different injection pressures when the inner or outer nozzle operates respectively and together, and the spray angle was obtained by binarization processing. Sauter Mean Diameter (SMD) was measured by Malvern laser particle size analyzer. The test results show that the flared inner nozzle dominates atomization at low fuel injection pressure. As fuel injection pressure increases, the flat outer nozzle can generate greater momentum, which has a significant impact on the atomization cone angle during simultaneous operation, making the atomization cone angle between 60° and 102°. The circumferential uniformity of the outer nozzle and inner nozzle working simultaneously is higher, and the atomization cone angle is between the outer nozzle and inner nozzle working separately. By using a flared inner nozzle, the axial velocity of the liquid film was reduced by about 42.12% and the atomization cone angle was larger, which is more conducive to secondary atomization. SMD was reduced by about 19.6%.