It has the characteristics of non-contact, fast, convenient and intuitive, and overcomes the shortcomings of traditional thermometers, frontal thermometers, point thermometers and ear thermometers, which are only for individual measurement, time-consuming and easy to cross infection, and can control the spread of the epidemic and reduce casualties, and is very suitable for rapid temperature investigation in airports, docks, stations, hospitals and shopping malls and other places with large traffic.