The stability of the micro/nano-structure of calcium-silicate-hydrate（C-S-H）， as the main hydration product of ordinary silicate cement， significantly impacts the strength and durability of cement-based materials.The research progress of C-S-H molecular and colloidal structures in recent decades was reviewed， and the related research progress of micro/nano-structural stability， nano-mechanical property stability， and enhancement strategies of C-S-H under cryogenic environment were further outlined. Several critical issues in the current research of C-S-H structure under cryogenic environments were discussed， and an outlook on further research in this domain was proposed.