In recent years, global warming has led to frequent high temperature weather, and occupational groups who have been exposed to high-temperature environment for a long time are vulnerable to heat casualties due to the combined impact from multiple meteorological factors (temperature, humidity, wind speed, and thermal radiation). In order to strengthen the health support for high-temperature workers, it is necessary to monitor the environment heat intensity of high-temperature environment in real time to guide relevant actions. Wet bulb globe temperature (WBGT) index takes into account multiple meteorological factors such as temperature, humidity, wind speed, and thermal radiation, and can more scientifically evaluate the environment heat intensity than individual thermal environment factors, thus guiding high-temperature operations for multiple working populations. This paper summarized the origin and development of WBGT index and its research and application status at home and abroad, and proposed possible development directions of the key technologies based on the WBGT index in China in the future.