Aiming at the problem that the infrared image of rotary kiln surface is fuzzy and the image details are not easy to distinguish, an infrared thermal image enhancement method is proposed based on the visual characteristics of rotary kiln surface. In this method, the infrared image gray level of the rotary kiln surface is mapped to the easily distinguishable area of the human eye by utilizing the difference of the resolution ability of the human eye in different gray levels, so as to improve the resolution ability of the human eye to the image details. The experimental results show that the method can highlight the edge of infrared image and reflect the high and low temperature area in the kiln in time. It is of great significance to avoid the red kiln accident caused by abnormal high temperature and ensure the kiln to operate economically and efficiently.