This study introduces measurement principle, measurement locations and methods of mercury free ther-mometer, and research status of mercury free thermometer to measure temperature is reviewed, the prospect of applica-tion prospect of mercury free thermometer is looking forward to, and put forward that medical institutions should ac-tively respond to the "mercury free medical care" action, give the specification for mercury free thermometer in mea-sures temperature and medical personnel management behavior, it truly realizes that, the mercury free thermometer is fast of accurate temperature measurement, safe of temperature measurement, and easy to use, it saves time and reduces the risk of clinical nursing of mercury to the environment pollution, and provides a reliable basis for clinical diagnosis and treatment of patients.