An infrared human body temperature measurement system based on an ARM processor is proposed. The system consists of a MLX90615 high accuracy medical digital infrared sensor, an ultrasonic sensor, an environmental temperature sensor, a master CPU and other external circuits. The MLX90615 sensor collects the infrared radiation from a human forehead and sends it to the CPU. Through temperature and distance compensation, the forehead temperature value is converted to the corresponding body temperature and is displayed in a liquid crystal display. The experiment shows that compared with other systems, this infrared human body temperature measurement system has its functions of environmental temperature compensation and distance compensation. It can reduce the effect of environmental temperature and distance greatly and can be used to measure human body temperature accurately, quickly and contactlessly.