In recent years, zirconia ceramic, as a preferential choice for teeth restorations, is used as fixed partial dentures and implants due to its excellent mechanical properties, favorable biocompatibility and aesthetic properties, thus significantly shortening the performance life and seriously damaging the reliabilities. However, zirconia ceramic easily occurs low temperature degradation (LTD) of t-m transformation in humid environments. This paper illustrated the characteristics, mechanism and kinetics of LTD, as well as the conventional characterization methods of LTD phenomena and new methods such as optical coherence tomography and focused ion beam. It is also shown the main factors affecting the aging phenomenon, and emphasized the inhibition methods of LTD. By developing materials system and improving processing technology to enhance the strength, fracture toughness of zirconia and to solve the LTD of zirconia, and to meet the needs of people for their health functionalization, zirconia ceramic will be widely applied in the dental restoration field.