Abstract: With the development of the "Belt and Road" Initiative, the National Maritime Strategy, and Regional Economic Integration Strategic Layout, a large number of rail transit, highway, railway, and other large-scale infrastructure projects are facing the challenge of crossing rivers and seas. Starting from the Nanjing Yangtze River Tunnel, Shanghai Yangtze River Tunnel, and Wuhan Yangtze River Tunnel, by introducing, assimilating, practicing,and re-innovating of shield tunnelling technology, China′s underwater shield tunnel technology has entered a rapid development stage. A large number of completed and under-construction super underwater shield tunnel projects have greatly promoted the innovation, development, and progress of underwater shield tunnel technology in China and even the world, breaking through a series of technical bottlenecks in shield equipment, design, construction, operation, and maintenance of underwater tunnel. The article systematically elaborates the three major elements of shield technology and their connotations, namely soil-water stability, shield equipment and control, structural safety and waterproofing, analyzes the current status and development trend of ultra-large diameter underwater shield tunnel technology at home and abroad, summarizes the important innovative achievements in ultra-large diameter underwater shield tunnel technology in recent years, and proposes the technical challenges, countermeasures, and engineering application prospects of underwater shield tunnel with large diameter, long distance, high water pressure, and complex geological conditions.