The present invention provides: a high manganese steel for a low temperature; and a manufacturing method therefor, the high manganese steel comprising 0.3-0.8 wt% of C, 18-26 wt% of Mn, 0.01-1 wt% of Si, 0.01-0.5 wt% of Al, 0.1 wt% or less of Ti (excluding 0%), 1-4.5 wt% of Cr, 0.1-0.9 wt% of Cu, 0.03 wt% or less of S (excluding 0%), 0.3 wt% or less of P (excluding 0%), 0.001-0.03 wt% of N, 0.004 wt% or less of B (excluding 0%), and the balance of Fe and other inevitable impurities, wherein the microstructure is a single-phase austenitic structure, and the grain size of the austenitic structure is 50 µm or less.