Abstract: Since traditional histogram equalization and gray-scale transformation algorithms could not realize the enhancement of the target in the infrared image effectively, an adaptive algorithm for infrared target enhancement is presented. The algorithm is used to filter out random noise in infrared image by median filtering, and divide the image into target section and background section by histogram, suppress background and enhance target feature by linear weighted overlap. The experimental result shows that this algorithm could automatically choose the threshold of histogram segmentation according to the gray scale characteristic of the target. It can also increase the contrast, decrease the noise and suppress the background. The algorithm performs well for target enhancement in the infrared image whose histogram has two local peaks when target and background pixels are similar.