As major substitution to supply oil and gas resources for human needs, deepwater (also known as deep-sea) has become strategic places for many countries. Compared to land and shallow waters, science and technology play an important role in the exploration and development of deepwater oil and gas. By systemic research and detailed analysis of geological characteristics, exploration technology (seismic technology and non-seismic technology) and mining technology (risers technology, development wells’ drilling technology, completion and recovery technology) of deepwater oil and gas, future trends of the science and technology of deepwater oil and gas were summarized in combination with the development plans of major international oil companies.