This equipment inherits the technical characteristics of low energy consumption, high efficiency, fully automatic control,l and stable operation of the cascade sludge dewatering machine. It can directly contaminate the sludge in the secondary sedimentation tank rapidly and continuously, and the sludge concentration after concentration and separation is stable and adjustable in the range of 90%-96%. After adopting this equipment, there is no need to build a concentration tank, reducing infrastructure investment and land area. Effectively reduce the odor and phosphorus release caused by sludge in the thickening tank, reduce the work burden of subsequent treatment, and greatly improve the capacity of sludge dewatering or deep dewatering equipment. Stacked screw thickeners can be used as pretreatment equipment for sludge dewatering and deep dewatering systems, for high-pressure elastic press, high-pressure diaphragm plate frames, or other dewatering equipment.