Abstract: Large Eddy Simulation (LES) and Discrete Particle Method (DPM) were used to simulate the oscillating dispersion of the granular flow in the coaxial jet. The gas phase was modeled by LES and the particle particle collision was considered using hard sphere model. The influence of the void fraction was also considered. Through the user define function of Fluent, this model was carried out in Fluent. The simulation results revealed that LES DPM can be used to model the granular flow in the coaxial jet. The flow field of the oscillating dispersion was obtained, which deepened the understanding of the oscillating dispersion.