The invention belongs to the technical field of metallurgy and particularly relates to rare earth superstrong steel and a preparation method thereof. According to the rare earth superstrong steel andthe preparation method thereof, a micro amount of rare earth element is added in maraging steel, the using amount of Ni is reduced, Co for use is eliminated, and cost is remarkably lowered. The tensile strength of the rare earth superstrong steel obtained due to the preparation method is not lower than 2000 MPa under the room temperature of (20 DEG C), the extending rate is not lower than 9%, hightensile strength and excellent toughness are achieved, and the problem that traditional maraging steel is high in strength, but low in plasticity is solved.