<p>Based on the test data of rock material under different confining pressure and freeze-thaw cycle, the statistical damage model parameters related to the confining pressure level are determined, and the microelement strength of rock can be directly measured by axial strain; Using the inflection points in the damage evolution process of freeze-thaw rocks, the strain hysteresis factor, which characterizes the peak strain and model parameters, was obtained, the variation characteristics of axial strain of rock material from peak strength to residual strength in the post-peak region are revealed, and the definition of rock brittleness and plasticity and their value ranges were achieved by the model parameters; The inflection point strain is defined as the axial strain when the peak stress drops to the residual strength, the damage value at the inflection point strain is defined as the ultimate damage, a ultimate damage model under the coupled action of freeze-thaw and stress is established. The research results indicate that axial strain is sensitive to the brittle characteristics and ultimate damage of rocks under low confining pressure, and the inhibitory effect of low confining pressure on the ultimate damage of rocks subjected to different numbers of freeze-thaw cycles is not obvious; Under the action of low freeze-thaw cycle, increasing confining pressure has a significant effect on inhibiting the development of rock damage or the expansion of pores and fractures; Under the influence of high confining pressure and numerous freeze-thaw cycles, rock materials gradually exhibit the accumulation of freeze-thaw damage, the weakening of confining pressure constraint and the damage threshold effects.</p>