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.