Spiral sand-Stone-Washing Machine is widely used for washing separation, classification and removal of extraneous materials and so on in such industry as metallurgy, building materials, and water resources and hydropower, etc, and it is applicable for washing separation of fine and coarse materials, especially of sand for building and road construction. The screw sand-washing machine has the advantages of reasonable structure, convenient maintenance, large processing volume, less power consumption and high cleanness. The novel seal structure and full closed oil bath transmission device and adjustable overflow weir plate ensure that this series products possess the features of high efficient, durable, clean, favorable dehydrate effect, stable fineness of finished materials.