Abstract: A study is made of the general technical points at issue regarding heavy medium coal separation process, particularly the process involving the use of large-sized 3-product H. M. cyclone. The study shows that apart from the prerequisite of maintaining a stable separationg density, the principle of keeping dynamic equilibrium of content of fine coal in circulating medium needs to be followed—a decisive factor for ensuring the stable operation of the heavy medium system throughout the separation process. Based on the quantitative analysis made through process flowsheet related computation, the author presents a clear interpretation of the following hot points at issue relating to heavy medium separation process: energy consumption of medium pump and energy-saving measures; comparison of advances of 3 kinds of cyclones—gravity-fed cyclone treating undislimed coal; pressure-fed cyclone treating dislimed coal and gravity-fed cyclone treating dislime coal; the purpose of splitting up medium flow and functions of split flow ; the significance of coarse slime separation; and the use of shallow-bath heavy medium separator to make high-density separation for raw coal deshaling and disliming. The study made is intended to promote the high-quality development of coal preparation technology.