Aiming at the aging deformation of turbine blades in turbine engines under complex stress, Waspaloy nickel-based alloy was taken as the research object to carry out aging treatment and complete quasi-static high temperature mechanical tensile tests of Waspaloy nickel-based alloy at 600℃, 700℃ and 750℃. The flow stress of Waspaloy nickel based alloy at high temperature plastic section was predicted by Ludwik and Hollomon empirical formulas, and the mean error (Er) and root mean square error (RMSE) were introduced to evaluate the accuracy of the flow stress prediction. The results show that the hardness of Waspaloy nickel-based alloy is improved effectively after aging treatment, but its plastic properties are reduced. The tensile strength and elongation of Waspaloy nickel-based alloy are negatively correlated with the loading temperature in the range of 600°C750°C. Ludwik model owns higher accuracy than Hollomon model in flow stress prediction, but there is a still large error in flow stress prediction in high temperature and high strain region. Based on the Ludwik model, the exponential term is introduced, and the modified Ludwik model have a better prediction result in the flow stress of Waspaloy nickel based alloy at high temperature plastic section.