Aiming at the development of typical deep-water oil and gas fields in South China Sea, combined with Lingshui 17-2 deep-water gas field development project, the concept of a three-column high efficiency large semi-submersible production storage and offloading platform is proposed with 20 000 t topside payload and 20 000 m3 oil storage. Compared with the existing four-column semi-submersible production platform, the three-column concept platform design reduces one set of column-pontoon-mooring system, utilizes light-weight triangular truss structure design for the topsides, and highly efficient oil-water displacement technology for oil storage. Thus the payload ratio is significantly increased, the total cost of construction and installation is significantly reduced, and an efficient low cost technical solution can be provided for the development of deep-water oil and gas fields in South China Sea.