Underwater rock-socketed steel sheet pile cofferdam and construction method thereof

The invention discloses an underwater rock-socketed steel sheet pile cofferdam. The cofferdam comprises a fence, an inner support fixed in the fence and a fence inserting groove formed in an underwater bottom foundation rock stratum, wherein the bottom of the fence is inserted into the fence inserting groove, an inner anti-seepage body is arranged in the fence inserting groove and located on the inner side of the fence, an outer anti-seepage body is arranged in the fence inserting groove and located on the outer side of the fence, a slope toe anti-seepage body is arranged at the joint of the outer side of the fence and the foundation rock stratum at the bottom in water, and a plurality of pieces of anti-seepage soil cloth dividing the slope toe anti-seepage body into a plurality of layers are arranged in the slope toe anti-seepage body. The underwater rock-socketed steel sheet pile cofferdam is good in water stopping effect, convenient to construct and capable of reducing the construction cost. The invention