<p>Permafrost slope disasters affected by climate change and human activities have shown an intensifying trend, posing threats to infrastructure and human settlements. Based on previous research and unpublished findings, this paper systematically analyzes and summarizes the physical mechanisms, key controlling factors, research methods, and prevention and control technologies of permafrost slope instability. We propose a new insight that freeze-thaw exposed patches are an important trigger for slope instability. The high temperature on the surface of freeze-thaw patches and freeze-thaw cracks accelerates local hydrothermal erosion. The sliding surface of permafrost landslides is the soil-ice interface, which is generally horizontal and located at a depth shallower than the permafrost table in most cases. Furthermore, it can only occur between September and November, independent of seismic activity. Further research on the mechanism of permafrost slopes should places greater emphasis on the roles of precipitation infiltration and hydrothermal erosion-prone patches. Mitigation measures for permafrost slope disasters should consider the coupled hydro-thermo-mechanical-salt effects.</p>