The invention discloses a full-dry-type optical cable and a forming method thereof. The optical cable comprises optical fiber branch pipes, an elastic pipe, structural parts, a main water-blocking tape, an outer cladding layer and an inner cladding layer, the optical fiber branch pipes are arranged in a surrounding mode, and the elastic pipe is arranged in the center of the optical fiber branch pipes which are arranged in the surrounding mode, and is a hollow rubber hose; each optical fiber branch pipe comprises branch water-blocking tapes, an optical fiber layer and a casing pipe, the branchwater-stopping tapes are laid at the upper end and the lower end of the corresponding optical fiber layer, and the outer parts of the optical fiber layer and the corresponding branch water-stopping tapes are subjected to injection molding to form the corresponding casing pipe; the structural part is arranged between every two adjacent optical fiber branch pipes, the inner cladding layer covers theouter parts of the optical fiber branch pipes and the structural parts, the main water-blocking tape covers the inner cladding layer, and the outer part of the main water-blocking tape is subjected to injection molding to form the outer cladding layer. The optical fiber density of the full-dry-type optical cable is high; meanwhile, through the arrangement of the elastic pipe, a good effect of buffering and protecting optical fibers is achieved, multi-layer water and moisture resistance is achieved, and the effective service life of the optical cable is prolonged.