Abstract: Semi-submersible crane vessel (SSCV) is one of the most important equipment to develop deepwater oil and gas field. With a lot of equipment on board, the general arrangement plan needs to consider the ship's seakeeping performance, stability, structure strength, equipment layout, construction difficulty, cost and other factors, so it is a tough assignment. We summarize the experience in ship hull optimization, deck box arrangement, column arrangement, and pontoon arrangement. Such a research may provide a reference for further domestic study.