A combined discrete and continuum model was developed to study coal-medium flow in dense medium cyclones (DMCs). In the model, the motion of coal particles is obtained using the Discrete Element Method (DEM) which applies Newton’s equations of motion to individual particles, and the flow of medium fluid as a gas-liquid-magnetite mixture by the Computational Fluid Dynamics (CFD) based on the Navier-Stokes equations associated with the volume of fluid (VOF) and mixture multiphase flow models. The simulated medium and coal flows were validated against the measured pressure drop, overflow and underflow medium densities, and partition curves for different sized coal particless. It is demonstrated that the loading of coal particles obviously influences the pressure, density and velocity distributions of medium flow. The highest coal-medium interaction force occurs in the region just under vortex finder. The most intensive particle-wall interaction force occurs at the outer wall of vortex finder. The model provides a major breakthrough in understanding the detailed mechanisms of DMC operation and a convenient and cost-effective way to investigate the effects of variables related to geometrical, material, and operational conditions on the performance of DMCs.