Steel sheet pile is a kind of steel with lock mouth, its section has straight plate shape, groove shape and Z shape, etc., there are various sizes and interlocking forms. The common ones are Larsen style, Lackawanna style, etc. Its advantages are: high strength, easy to drive into the hard soil; Can be used in deep water construction, if necessary, diagonal support to become a enclosure. Good waterproof performance; Cofferdam can be composed of various shapes according to needs, and can be repeatedly used, so it has a wide range of uses.