Semi-submersible ships are mainly used to transport various major objects that are not suitable for disassembly, such as large-scale offshore engineering equipment, large industrial modules and military ships. In 2007, Shanghai Shipbuilding Research and Design Institute undertook the basic and detailed design of the 20,000-ton self-propelled semi-submersible vessel "WISH WAY". After several key technologies were tackled, the vessel was successfully delivered in September 2010. The successful design and construction of "WISH WAY" has broken the monopoly of European design companies. As the first self-propelled semi-submersible vessel independently developed and designed in China, it has complete independent intellectual property rights, and multiple technical indicators have reached or exceeded international levels. "WISH WAY" successfully completed its first international commercial operation in October 2010. All major systems and equipment are operating stably and fully meet the design requirements of the shipowner. This international commercial operation voyage is an ice-breaking journey in the field of semi-submersible ship design in my country., a milestone. So far,"WISH WAY" has completed many transportation tasks and has been highly recognized by shipowners and the industry. Rapidity is an important indicator of the type of transport ship. The actual ship trial of this ship shows that the speed can reach 15 knots at the maximum draft, which is better than that of similar types of ships in the world. The ship adopts electric-driven short shafting propulsion method, which not only improves propulsion efficiency, but also reduces costs, which is conducive to energy conservation and emission reduction. The ship can dive to 19 meters under the condition of loading 10% oil and water, when there is no cargo on the deck, and there is basically no trim in the floating state. The ship is designed to adopt a "fully integrated monitoring, alarm, and control system". The system is highly integrated, powerful, clear human-machine interface, easy to operate, and has strong safety and redundancy. The main innovations are: 1. Based on the unique characteristics of the semi-submersible vessel, the overall plan, line shape, general arrangement and reserve buoyancy were optimized, and excellent indicators such as diving depth, lifting time, stability change, speed and energy consumption were successfully obtained; 2. A simple, reliable and efficient power combination method of "electric drive and conventional propulsion" has been adopted, and a highly automated centralized monitoring system, a full-ship power management system and a 24-pulse propulsion system have been established, which effectively improves ship energy efficiency management and reduces ship energy consumption throughout the operation process; 3. The power management system has functions such as full-optical fiber redundant power station management, intelligent switching of diesel engine power distribution modes, fully automatic voltage regulation, dynamic retention of heavy-duty inquiry power and unbalanced mode operation; 4. We have independently developed a marine multimedia comprehensive data processing system, which realizes real-time transmission of ship-shore management data and remote automatic statistical analysis. One paper has been published on this research result: "Overall Performance Design of Semi-submersible Ships", Shanghai Shipbuilding (No. 2, 2011). Shanghai Shipbuilding Research and Design Institute tracks advanced technologies at home and abroad, explores, decomposes and studies key technologies for this ship type, and forms the ability to independently develop and design large-scale self-propelled semi-submersible ships. The realization of full-scale ship construction enriches my country's ship product structure and enhances my country's shipbuilding industry. Technical level and international competitiveness. The successful construction of this ship type has greatly improved the shipping strength of domestic major parts and broken the monopoly of foreign countries on this type of shipping market. At present, the semi-submersible ship market is very active. The successful R & D and design of this ship type and the research on key technologies have great reference significance, and play a positive guiding role in the technology promotion and industrialization of semi-submersible ship products. The transportation volume of major pieces at sea in my country has shown a rapid growth momentum, and the domestic and foreign shipping demand for major pieces has also reached a growth peak. With the current shipping capacity of domestic semi-submersible ships, it is far from meeting market demand, so this project has good market and application promotion prospects.