The infrared image of sulfur hexafluoride (SF6) has low contrast and blurred texture details and it is difficult to enhance leakage areas. An improved SF6 infrared image enhancement algorithm based on adaptive histogram equalization (CLAHE) with limited contrast is proposed. First, the original image is divided into basic image and detail image by bilateral filtering. Then the CLAHE algorithm is used to process the basic image and improve the contrast of the leakage area. And the detail image is transformed by piecewise linear transformation and Laplace transform image. It can edge image of highlighted image. Finally, the two images are linearly stacked to reconstruct the final infrared image, and the image enhancement is realized. The experimental results show that the enhancement effect of the algorithm on the leakage area of the SF6 infrared image is better than that of several common infrared image enhancement algorithms. It not only effectively suppress the noise and improve the contrast of the leakage area, but also highlight the edge of the leakage area and enrich the detail information.