Abstract: This paper aims at the abnormal phenomenon that the weighing coal quantity of unit 4 coal feeder of Xinyang Power Generation Co. , Ltd. is lower than the actual coal quantity entering the coal mill twice in a month, develop corrective actions. By summing up the phenomenon that the current of coal mill and coal feeder increases and the rotating speed of coal feeder is too high during the operation of the unit, some experience has been accumulated for analyzing the abnormal weighing of coal feeder.