Abstract: Back filling,especially in the case of mining in thin and flat dipping vein,is always discussed and difficult.A new technology of quick back filling with the help of separation curtain has been developed and successfully tested in the mine.By using this technology,the filling material slurry will reach a density of 78%—80% within 25min and the filling material will demonstrate a supporting function to the roof of goaf within 60min which helps very much in improving the safty of stoping area.In addition,the technology possesses the advantage that mining and filling can be conducted simultaneously which means an increment of productitity.