Abstract: This paper discussed how to control the thickness of cotton lap with a fuzzy control system made up of single-chip processor.The system made use of program and applied fuzzy algorithm and control strategy.Its real-time data acquisition and control system consisted of keyboard,A/D or D/A converter,displacement sensor,motor and frequency governor.The old speed regulating system of the scutcher was replaced with the fuzzy control system which regulated the speed of cotton feeding roller of the scutcher in such a way that the cotton feeding in unit time was kept constant.The practical results show that it has improved the accuracy and dynamic response and reduced lap irregularity.