Abstract: Aiming at the problems such as single product,low separation precision and large clean coal losing of the traditional thermal coal separation process,National Science & Technology Tangshan Branch invented three products cyclone with double medium feed without pressure.This paper introduce the structure and the separation principle, and compared the traditional thermal coal separation process and the double medium feed without pressure three products cyclone separation process.The product's application in Baiyan Coal Preparation Plant of Chongqing Songzao Coal-fired Power Limited Company prove that the product has some advantages such as large processing power,high clean coal recovery rate and flexible products.On the other hand for the double medium feed lowing feeding pressure,and reducing the wear and tear of the whole equipment,the product has a superiority of saving investment and operating costs.The R&D and application success of three products cyclone with double medium feed without pressure find a new method for the fine coal separation of power coal preparation plant.