Due to the defect of the detector′s principle, the images taken by the infrared thermal imager have low contrast and unobvious details. Contrast limited adaptive histogram equalization(CLAHE)can enhance the contrast of infrared images. But the parameters need to be adjusted manually since they cannot adapt to different scenes. As an intelligent swarm optimization method, cuckoo search algorithm has a strong ability to search for optimal solutions. In this paper, the cuckoo search algorithm is used to obtain the optimal parameters of CLAHE algorithm in different scenes, and the contrast of infrared images can be adaptive enhanced. The experimental analysis shows that the improved algorithm is feasible and adaptable.