Abstract: For high-density separation of mineral,the conventional single-cone DSM H. M. cyclone is converted into a double-cone version with gradually varied taper angles. The upper conical part of the cyclone has a larger taper angle for rapid thickening of suspension and,hence,increase of separation density while the lower conical part assumes a smaller taper angle for attaining a larger separation space and a higher separating efficiency. Numerical simulation of the double-cone cyclone’s internal flow field is made by means of Fluent software,and the result is compared with that of the conventional DSM H. M. cyclone. The result of comparison shows that the flow field of the double-cone version is more suitable for high-density separation of minerals.