Abstract: In order to solve problems of frequent fault and bad product caused by original manual control for press filter feed in Gaozhuang coal preparation plant,put forward a method of controlling feed based on micro flow monitoring unit built by jacketed ultrasonic flowmeter and PLC,so that filter press feed is subject to flow control instead of time control,achieved flexible control by feed flow to start or stop feed pump. After upgraded control of filter press feed,automatic control of this system is improved,with more stable equipment in operation.