Abstract: The present disclosure discloses a preparation method of a powder metallurgy (PM) superalloy with high strength and plasticity. Under the multi-field coupling action of a thermal field and a force field, the PM superalloy is obtained in a high-temperature graphite mold by using the method of conducting heat preservation and oscillating-pressure sintering in two steps. Under the action of a circulating pressure, rearrangement of powders and discharge of pores are promoted, and therefore, the PM superalloy is sintered and formed. The present disclosure further discloses a PM superalloy prepared by using the method above. The PM superalloy has the characteristics of low grade of prior particle boundary defects, uniform grain refinement and high density. The sintered PM superalloy obtained in the present disclosure has a yield strength of 955 MPa, a tensile strength of 1,437 MPa and an elongation of 31.9%, and has high strength and plasticity.