Abstract: In order to tackle the trouble of frequent blocking of the separator's upward current system, an optimum scheme for preventing the occurrence of such troubles is proposed, following an analysis of the structural design and working principle of the upward current system and the factors affecting the normal operation of the system, and by referring to the operational experience gained by Shangwan Coal Preparation Plant over years. Practice shows that under the identical working conditions, the implementation of the scheme has led to sharp decrease of the frequency of occurrence of the plugging trouble and medium consumption, making it possible for the plant to save a power cost of 100, 800 yuan for operating the separator each year.