Permafrost degradation on the Qinghai-Tibet Plateau is accelerating under climate warming, causing roadbed settlement, waterlogging, thawing interlayers, and long-term instability in high-altitude highways. The study reviews global and Chinese permafrost engineering practices, identifies the mechanisms behind pervasive subgrade deformation, and highlights challenges in current “permafrost-protection” design approaches. It proposes a third design principle — proactively improving foundation conditions — advancing from passive protection to active treatment. The work further summarizes shallow and deep foundation treatment techniques, evaluates engineering applications, and outlines development trends such as improved hydrological investigation, long-term monitoring, and novel construction materials.