Abstract: High-manganese austenitic steel, known for its excellent comprehensive properties of ultra-high strength and toughness, low magnetic permeability, high fatigue resistance, and low production cost, is widely used in critical industries such as aerospace, petrochemical, and rail transportation. The deformation mechanisms of high-manganese austenitic steel, including martensitic phase transformation, twinning, and dislocation movement, are mainly determined by the stacking fault energy (SFE), which is significantly affected by alloying elements and deformation temperature. The influence of alloying elements such as C, Mn, Si, Nb, Ti, V, Mo, Al, Cr, and rare earth elements on the SFE, microstructure, and mechanical properties of high-manganese austenitic steel was reviewed. It is concluded that elements including C, Mn, Nb, Ti, and Al increase the SFE, thereby enhancing the percentage elongation after fracture, while Si, Mo, and Cr decrease the SFE, which is more conducive to improving tensile strength. An optimized alloy composition ratio is recommended as follows: C < 0.6%, Mn > 18%, 0.3%~0.6% Si, 0.29%~0.3% Nb, 0%~0.15% Ti, 0.15%~0.3% V, 0.8%~1.3% Mo, 1%~3% Cr, and Al < 2%. Moreover, the appropriate addition of rare earth elements can purify the molten steel, modify the morphology of inclusions, refine grains, and inhibit carbide precipitation, thereby further improving the overall mechanical properties of high-manganese austenitic steel. This review provides valuable guidance for the composition design and engineering application of high-manganese austenitic steels and their corresponding welding consumables.