The spiral sand-washing machine is suitable for washing, grading, impurity removal and other operations in metallurgy, building materials, hydropower and other industries, and is used for washing fine-grained and coarse-grained materials. It is suitable for sand and gravel in building construction and road construction. The spiral sand-washing machine has low power consumption and high cleaning performance. The good sealing structure, fully enclosed transmission device, and adjustable weir plate ensure that the product is efficient and durable, has good cleaning and dehydration effects, and maintains the stability of fine-grained products.