Stack screw sludge dehydrator is a special equipment for sludge dewa tering, it uses the principle of double screw type enrichment dehydrator, through the sandwich screw propeller, the sludge in the screen tube along the spiral axis, so that the sludge into the screw press, and then the screw press sludge along the screen tube of the specified road for enrichment and dehydration, in the continuous rotation of the press, the sludge Separat e from water for efficient dehydration.