In order to optimize the subsequent rolling process, the Gleeble-3800 thermal simulator was used to test the isothermal constant strain rate compression of the as-rolled 254SMo super austenitic stainless steel. The thermal deformation behavior and microstructure evolution of 254SMo in the temperature range of 900-1100℃ under the strain rates of 0.005-5 s^-1 was studied. The results show that the peak stress reduces with the deformation temperature increasing and the strain rate decreasing, the single peak characteristic of flow curves become obvious, which indicates that 254SMo is prone to dynamic recrystallization under high temperature and low strain rate;three forms of Arrhenius The prediction accuracy comparison of the three forms of Arrhenius constitutive equations shows that the exponential form has the highest accuracy, the correlation coefficient is 97.496%, and the deformation activation energy is 546 kJ/mol.