The maritime power strategy promotes the country to make deep exploration and reasonable development in the South China Sea. It is essential to make full use of renewable energy surrounding the island and build a multi-energy complementary island microgrid. The island microgrid can realize safe and reliable power supply to guarantee island development and residents’ daily life. Based on technological achievements of multi-energy complementary island microgrid of China Southern Power Grid in the South China Sea, the difficulties in island microgrid caused by the natural climate and social factor are analyzed, multi-energy complementary solutions, capacity configuration and storage system are introduced, and zone control strategy based on source-grid-load-storage interaction is proposed in order to maintain stable operation of island microgrid. The development trend from island microgrid to island comprehensive energy network is also discussed finally.