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The hot compression behavior of the nickel-based heat-resistant alloy C-HRA-2? was investigated by a Gleeble-1500 thermo-mechanical simulator with the deformation temperature range of 950–1150 °C and the strain rate of 0.001–10 s?1. The constitutive equation of the alloy was established by using a hyperbolic sine function, and the peak stress followed a power law relationship with the Zener–Hollomon parameter (Z). The activation energy was about 446 kJ mol?1 for the whole hot deformation domain in this alloy. The optimum hot deformation condition was obtained in the temperature range of 1050–1150 °C and the strain rate range of 0.005–0.1 s?1. Unsafe domains during the hot deformation would occur in the strain rate range of 0.1–10 s?1 with inhomogeneous microstructure and high-density twins in the alloy. The dominant nucleation mechanism of dynamic recrystallization (DRX) was continuous dynamic recrystallization with sub-grain rotation at high strain rate, while DRX at low strain rate was discontinuous dynamic recrystallization with original grain boundaries bulging.