Abstract: Compared with three-product dense medium cyclone,the process of primary separation and secondary separation with two product dense medium cyclone is flexible and easy to control the quality of middlings,but added the link of medium draining of underflow of primary separation. Based on the design examples of three preparation plants,compared the advantages and disadvantages of medium draining of underflow by sieve bend,sieve bend combined with horizontal vibration screen,and fixed screen combined with banana screen,on this basis,presented the solutions against the effects of different medium draining methods on medium balance in system,which solutions all achieved desired effect in their application.