With the continuous promotion of the national western development strategy, as well as the revitalization of the Northeast old industrial base, many water conservation, transportation and mining projects are planned more frequently in permafrost regions at high altitudes and latitudes Rather than conventional geological areas. Because of the periodic changes in air temperature, the properties of geotechnical materials have changed greatly in permafrost regions, resulting in many new geotechnical engineering challenges. It is particularly difficult to evaluate the stability of open pit rock slopes and cutting rock slopes formed by excavation using conventional methods. Based on the theme that the essence of slope stability of fractured rock mass in cold region is the thermo-hydro-mechanical(THM) coupling affected by freeze-thaw cycle, this paper examines the stability of frozen rock slopes from the perspective of the failure mechanisms, types of failures, mechanical properties of low-temperature rock masses. On the base of the study of stability, this paper proposed the classification of frozen rock slopes and a time-varying evaluation method for the stability of frozen rock slope, which takes into account freeze-thaw damage of rock mass, rainfall infiltration in summer and crack propagation in winter, and the numerical simulation method is used for preliminary verification. This paper can deepen scholars' understanding of rock fracture slope in cold area and promote related research work.