According to the theory of heat radiation and the temperature measurement principle of an infrared thermal imager, a platform for testing clothing comfort based on the infrared thermal imaging technology is built. The surface temperature field distribution of the clothing worn by a person is directly measured by using an infrared thermal imager in different environment. The collected thermal images are used to analyze the temperature field and judge the change of the actual temperature of the clothing worn by the person, so as to deduce the thermal insulation properties of the clothing and the cloth used. The objective experiment result and the subjective assessment result are analyzed. The analysis result shows that among three experimental clothing, the clothing made of the cloth containing 50% soybean fiber and 50% cotton has the best thermal-wet comfort. This evaluation method based on the infrared thermal imaging technology is effective and can be used as one of the important tools for judging the thermal comfort of clothing.