Abstract: The thermal simulation compression experiment of GH4080A superalloy was carried out and the deformation behavior was analyzed under the deformation temperature of 1000-1060 ℃and strain rate of 0.1-50 s^-1. Based on the equilibrium principle of work hardening, dynamic recovery and dynamic recrystallization softening in the process of hot deformation, the relationship between critical strain, peak strain and Zener-Hollomon parameters was determined. The dynamic recrystallization volume fraction of the alloy during hot deformation was calculated to establish the dynamic recrystallization volume fraction model, which can quantitatively predict the proportion of dynamic recrystallization at different hot deformation parameters. The volume fraction of dynamic recrystallization predicted by the model is almost consistent with the experimental results, which can provide theoretical support for the optimization of forging process parameters of GH4080A alloy.