The competition among countries in the marine field, whether political, economic or military, is essentially the competition of science and technology. The competition of marine science and technology focuses on deep-sea high-tech. In recent years, more and more countries have raised the development of deep-sea technology to a national strategic level and increased the activities to explore the deep sea. How to ensure the safety of deep-sea activities and improve the deep-sea emergency response capability is a new problem facing China’s deep-sea salvage. This paper comprehensively analyzes the cases and related technologies of deep-sea salvage at home and abroad, summarizes the technical system of deep-sea salvage, and prospects the future development of related fields.