Abstract: The raw coal is found difficult in screening, which causes the calorific values of its certain size fractions of the cleaned coal to be reduced rather than increased. To tackle this problem, the Selian No.2 Mine Coal Preparation Plant switches to the use of the flip-flop screen for in-depth screening of the raw coal. Practice shows that with the use of the method for screening the high-moisture raw coal with the same property, the efficiency of screening at a size of 6mm is up to 75% and the number of the coal slurry water treatment equipment can be cut by 45%. Because of the increase of calorific value of clean coal products, a favorable socioeconomical result has been obtained.