ODS nickel-based superalloys with different contents of Y2O3 (mass fraction from 0% to 10%) as dispersion phase were prepared by powder metallurgy (PM) method by different sintering technologies. Effects of oxide content and sintering temperature on the mechanical properties of ODS nickel-based superalloys were studied. Results reveal that the sample with 1.5% Y2O3 sintered at 1260 °C for 2 h has optimal comprehensive properties, whose relative density is 90.9% and tensile strength is 669 MPa. The phases of alloy powder prepared by different milling technologies were determined by XRD. The mechanism for the effect of Y2O3 content and sintering temperature on the mechanical properties of the ODS superalloys was analyzed through fracture microstructure observation and micro-area chemical composition analysis.