Abstract: A detailed review of the strengthening and toughening mechanisms, performance characteristics, and application potential of fully austenitic high-manganese steel in liquid hydrogen storage and transportation under extremely low-temperature environments is provided. It is demonstrated that the synergistic activation of twinning-induced plasticity and transformation-induced plasticity effects can be achieved through stacking fault energy regulation, endowing high-manganese steel with a combination of high strength, high ductility and excellent impact toughness at low temperatures. The addition of alloying elements such as Mn and Al can further increase the stacking fault energy and optimize the microstructure, thereby significantly improving the mechanical properties of the material in ultra-low-temperature environments. High-manganese steel exhibits outstanding cost advantages in the process of liquid hydrogen storage and transportation. Compared with traditional stainless steel, it can effectively reduce manufacturing costs. Meanwhile, abundant manganese resources in China provide a guarantee for its large-scale application. In addition, high-manganese steel possesses excellent diffusion coefficients and is regarded as a highly promising candidate structural material for liquid hydrogen environments. Compared with other similar materials, it can maintain superior mechanical properties under low-temperature conditions. However, many challenges are still faced during the engineering application of high-manganese steel, including continuous casting breakout, welding cracking, Mn vapor volatilization and hydrogen embrittlement sensitivity. Future research should focus on addressing the above challenges to promote the reliable application of high-manganese steel in extreme environments such as liquid hydrogen storage and transportation.