Abstract: The effects of deformation temperature (1100℃~1400℃) and strain rate (0.1s-1 ~ 0.001s-1) on the flow stress and microstructure evolution of Mo-14Re alloy prepared by powder metallurgy were analyzed by Gleeble 1500 thermal simulation test machine. The constitutive equation of Mo-14Re alloy was established by using Arrhenius model of hyperbolic sine. The results show that the flow stress of the Mo-14Re alloy prepared by powder metallurgy decreases with the increase of deformation temperature or the decrease of strain rate during hot deformation, and the true stress-true strain curve shows obvious work hardening and dynamic softening phenomenon. The dynamic softening behavior is mainly attributed to the dynamic recrystallization of Mo-14Re alloy at low strain rates (0.01s-1 and 0.001s-1) or high deformation temperature (>1200℃) during hot compression. The nucleation mode is grain boundary protruding nucleation. With the decrease of strain rate or the increase of temperature, the recrystallization of Mo-14Re alloy is mainly attributed to the dynamic recrystallization at low strain rates (0.01s-1 and 0.001s-1) or high deformation temperature (> 1200℃). The degree of recrystallization increases and the grains grow up. At 1400℃ and strain rate 0.001s-1, Mo-14Re alloy has been completely recrystallized.