The invention relates to a heat treatment process for regulating controlling the yield strength ratio of medium manganese steel. The heat treatment process of quenching and two-phase region high-temperature tempering is adopted. When the quenching temperature is Ac3+(20-60) DEG C, and hypoeutectoid steel is heated at Ac3, a ferrite is completely converted to the temperature of austenite, and the heat preservation time is 1.5-2.0min/mm; when the tempering temperature is Ac1+(10-70) DEG C, and the hypoeutectoid steel is heated at Ac1, the ferrite starts to be converted to the temperature of austenite, and the heat preservation time is 1.7-2.5min/mm. The yield strength ratio of medium manganese steel is regulated between 0.65-0.93 through the quenching and tempering process, and the yield strength is regulated between 500-690MPa.