Isothermal thermal compression test is conducted by adopting a Gleeble-3500 thermal simulator, the high temperature rheological behavior of GH2907 superalloy at the forming temperature of 950℃~1100℃, the strain rate of 0.01s_-1~10s_-1 and the strain of 60% is studied. The results show that the flow stress of GH2907 superalloy decreases significantly as the forming temperature increases or the strain rate decreases. The thermal deformation activation energy of the alloy is calculated by Arrhenius hyperbolic sine equation and Zener-Hollomon parameter, and its Q=463.043kJmol_-1. At the same time, the stress-strain curve of the superalloy has obvious dynamic recrystallization (DRX) characteristics, and the strain, forming temperature and strain rate all have a significant effect on the DRX volume fraction. Based on the stress-dislocation relationship and DRX kinetics, the mechanism-type constitutive models of the two stages of work hardening-dynamic recovery and dynamic recrystallization are established to describe the relationship between flow stress, strain rate and forming temperature. According to the error analysis, the correlation coefficient R=0.987, the experimental value is in good agreement with the prediction of the established constitutive equation, and it can be used to accurately characterize the thermal deformation behavior of superalloy.