The effects of deformation temperature (880–1200°C) and strain rate (0.001–1 s−1) on the hot deformation mechanism of Fe-23Mn-3Cr-0.3C steel were investigated through single-pass compression tests. The findings revealed that the flow stress of Fe-23Mn-3Cr-0.3C steel could be accurately represented by a constitutive equation based on the Arrhenius equation, with a high correlation coefficient of 0.996 observed between experimental values and the model. Moreover, a critical strain model for dynamic recrystallisation (DRX) was formulated. The study delved into the evolution of DRX using electron backscatter diffraction (EBSD) technology, uncovering two primary nucleation mechanisms: (1) discontinuous DRX characterised mainly by grain boundary bulging and twin-assisted nucleation and (2) continuous DRX characterised predominantly by sub-grain rotation.