<p>The entire process of damage and weakening of heterogeneous rock materials was described using the number of freeze–thaw cycles as a randomly distributed variable. The characteristic points and lower limit values of rock damage evolution were determined. The post-buckling behavior of freeze–thaw layered slopes was explored using the initial post-buckling theory, and the critical buckling load and bifurcation buckling load of the slope rock mass were given. A stability criterion for the equilibrium configuration of the rock mass structure was established. The results show that the critical load of the slope rock mass decreased monotonically with the Weibull distribution density function, and the increment of bifurcation load decreased exponentially with the density function. Under the Weibull statistical model with freeze–thaw cycles as the random distribution variable, the fatigue damage residual modulus of the rock material could be determined using the number of freeze–thaw cycles to reach the fatigue damage life of the rock material. The evolution characteristics of heterogeneous layered slope rock masses in cold regions, from initial buckling under critical load to bifurcation buckling under bifurcation load, and then to structural buckling and failure caused by material damage and weakening, express the mutual influence and coupling between structural stability and material degradation under the combined action of freeze–thaw cycles and defect loads.</p>