Abstract: The volume of fluid approach was coupled the Reynolds stress model and the discrete phase model combined with the Taylor analogy break-up instability breaking model to simulate the primary atomization and secondary atomization for the close-coupled annular nozzle by computational fluid dynamics software Fluent19.2, and the simulation was verified by experiment. The results show that the primary atomization resulted in the forming of an annular liquid film at the bottom of the delivery tube. The primary atomization at the tip of the liquid film was mainly the result of turbulent shear at the free boundary of the gas jet, and the diameter of the droplets formed by the primary atomization satisfied the normal distribution. As the outside of the dispersed droplet group contacted the gas jet, the secondary atomization gradually started from the outside of the droplet group to the core, but the droplets those did not contact with the gas jet maintained a high degree of superheat. The simulated diameter of the powder after secondary atomization by the close-coupled annular nozzle was in good agreement with test results, and the relative error was less than 5%, which verified the accuracy of simulation.