Abstract: In recent years, continuous breakthroughs have been made in the exploration and development of deepwater oil and gas resources in China. In particular, the successful undocking of HYSY-981, a deepwater semi-submersible drilling platform, has elevated deepwater drilling equipment of China to an advanced level in the world. However, in contrast with international advanced peers, the experience in deepwater drilling and completion in China is insufficient, operation and technology are at low level, the basic research at a theoretical level and other aspects are weaker. The paper reviewed the situation of research on deepwater drilling and completion in the South China Sea, and analyzed the technical difficulties existing in these operations. In consideration of existing challenges in the South China Sea, including special marine environment and geological conditions as well as long distances from the seashores, a series of key technologies and suggestions are proposed. It could be taken as the reference point and platform for the development of technologies and theories in deepwater drilling and completion in China, and to realize safe and efficient development of deepwater oil and gas resources in the South China Sea.