Kefid screw sand washing machine is mainly used for sand processing, electric pole factory, building work site and concrete dam, various sands classifying and dewatering. This sand washing machine adopts inclination of 15º, under the water tub, three weir plates form the sediment pool, the screw head is immersed in this pool, the screw is driven by electric motor through reducer rotating continuously, the fresh water is feeding from porous plate at bottom of sediment pool, this machine have three functions of washing, dewatering, classifying.