The invention discloses high-performance medium-manganese TRIP steel and a low-temperature processing forming method thereof, and belongs to the technical field of ultrahigh-strength steel. The methodcomprises the following steps of heating the cut medium manganese steel ingot to 600-800 DEG C and carrying out heat preservation for 0.5-1.5 hours, carrying out two-phase zone rolling, carrying outair cooling; then heating to 600-800 DEG C, and preserving heat for 5-10 minutes; transferring the medium-manganese TRIP steel plate subjected to austenitizing treatment to a stamping die, wherein thetemperature is reduced to by 50-100 DEG C, carrying out stamping forming, and carrying out pressure maintaining for 10-30 seconds, cooling to 180-250 DEG C along with the die; and heating to 250-450DEG C, preserving heat for 10-30 minutes, and carrying out air cooling, and obtaining a high-performance medium-manganese TRIP steel forming part. According to the method, the two-phase region is rolled, so that the C / Mn is prepared in advance and then is processed by a subsequent Q and P process, so that the C / Mn is prepared. According to the forming method, the rolling efficiency and the surfacequality of the stamped part are improved, the strength of the manufactured stamped part is high, the comprehensive performance is excellent, and the requirements of the target of the automobile industry are met.