According to the principle of screw sludge dewatering machine, we developed a new type of sludge thickening equipment-screw sludge thickener as the demand of market. Screw sludge thickener inherits advantages of screw sludge dewatering machine, like: automatic continuous operation, low energy consumption, high efficiency, running stable and excellent properties, directly concentrate the sludge in secondary sedimentation tank. This equipment can be used instead of concentrated tank, reduces the area as well as the civil engineering construction cost, and effectively reduce stench and phosphorus release of sludge concentration pool. This equipment can be used as pretreatment of sludge dewatering and depth dewatering equipment.