The screw dehydrator is mainly used for sludge treatment in municipal sewage, petroleum refining, brewing leather, printing and dyeing and papermaking, coal beneficiation, biopharmaceuticals, steel pickling, food processing and other industries. During the operation of the equipment, the sludge enters the filter drum from the feed inlet and moves to the discharge outlet under the push of the spiral blade. As the pitch of the spiral blade decreases gradually, the squeeze pressure on the sludge increases gradually. During the pressure maintaining period, the water flows out of the gap between the fixed ring and the floating ring to achieve thepurpose of dehydration. At the same time, the self-cleaning function is realized by the relative movement of the fixed ring and the floating ring to prevent the sludge from blocking the gap, and the dehydrated sludge cake is discharged from the discharge port under the push of the spiral blade. This product is designed and manufactured in strict accordance with "JB/T 12578-2015 screw sludge dewatering machine".