For infrared image with the characteristics of low contrast and low signal-to-noise ratio (SNR), an infrared image enhancement method based on median filtering and biological bionics is presented. Firstly, the median filtering is used for image de-noising, and then the image is enhanced by using biology vision model. Fi? nally, the enhanced image is obtained. A group of experimental results demonstrate that the presented algorithm can reduce the noise and highlight the image detail, and solve the problem of the low contrast in infrared image. Comparing with the traditional image enhancement methods of median filtering method with histogram equaliza? tion enhancement and weighting neighborhood averaging method with gray value transform, the SNR and peak signal-to-noise ratio (PSNR) of image both are advanced.