The invention discloses water injection settling type annular hoisting floating body equipment for dynamic cables. The equipment comprises a plurality of watertight subdivisions, wherein the watertight subdivisions are mutually connected and separated, are mutually connected to form an annular structure and comprise internal skeletons and external skins, water injection holes, exhaust holes and draining holes are respectively formed in each watertight subdivision, each watertight subdivision is connected with a lifting device through pull rods, one ends of the pull rods are connected with the watertight subdivision through plug pins, and the other ends of the pull rods are connected with the lifting device through lifting lugs. The water injection settling type annular hoisting floating body equipment can be applied to underwater construction of the dynamic cables and supporting facilities. Compared with a traditional solid floating design, the equipment has the advantages that the buoyancy of a floating block can be rapidly adjusted, and the construction is convenient; and the relative stability of underwater loaded objects is maintained, and the cables or pipelines connected with a terminal are not damaged.