Abstract: The conical structure of the tri-cone Angle hydrocyclone was studied by orthogonal experimental design and computational fluid dynamics.Firstly, the influence of cones from different angles on the separation effect of coarse coal slime was studied through orthogonal experiment. Then by using the method of CFD to three cone Angle of water medium cyclone, the internal flow field in numerical simulation of turbulent phase by using the Reynolds stress the RSM model, further DPM discrete phase model are adopted to simulate the three cone particles in water medium cyclone motion, analysis of internal flow field of the pressure, velocity distribution and solid particle trajectory, the results show that the three sections of the cone has influence on separation effect, influence degree for first cone > second cone >third cone; The first cone can obtain lower cleaned coal ash content, and the second and third cone can ensure higher cleaned coal yield within the required ash content range, providing reference for optimizing the cone structure parameters of the three-cone Angle hydrocyclone.