The isothermal compression test of GH625 alloy was performed on Gleeble thermal simulator. A series of true stress-strain curves under different deformation conditions were obtained. The processing map of GH625 alloy in different strains was constructed according to DMM model, and the following conclusions can be obtained through the analysis of processing map. There exists an area in the processing map of GH625 alloy where the power dissipation efficiency is higher than that in others areas. The temperature corresponding the area is 1100~1200 ℃ and the strain rate is 0.01~1.0 s-1. In this area the alloy has completed fully dynamic recrystallization. When the power dissipation efficiency is in the range from 0.4 to 0.45, the dynamic recrystallization grains become finer. At the peak efficiency of 0.47, the dynamic recrystallization grains grow up apparently. There exists a small area of rheological instability in the processing map where the temperature is low, while the strain rate is high, and the dynamic recrystallization grains are distributed along the adiabatic shearing edges. The practical parameters of production processing should be chosen in fully dynamic recrystallization area, and the manufacturing in the instability zone should be avoided. According to the comprehensive mechanical properties of high temperature deformation, the microstructure evolution and the processing map of the GH625 alloy, we can get a suitable processing area, which is =0.01~1.0 s-1，T=1100~1200 ℃