A rotary cement kiln is the core equipment in the production process of dry cement. The surface temperature of a rotary kiln can reflect the internal status of the rotary kiln. Therefore, to monitor the surface temperature of the rotary kiln in real time is very important for keeping the safe operation of the rotary kiln. To express the temperature distribution of the rotary kiln effectively, the three-dimensional thermograph generation of the surface temperature of the rotary kiln is studied. A pseudo-gray color coding model is used to map different temperatures into different colors. By incorporating an OpenGL technology creatively, realistic three-dimensional thermographs are displayed in real time. The in-situ test results show that the three-dimensional thermographs of the rotary kiln surface generated have the features of intuition, stability and reliability.