Abstract: Pointing at the difficulty in the edge detection of infrared image,the characteristics of the infrared image and its gradient image are analyzed,a daptive edge detecting algorithm based on Tsallis entropy of infrared image is proposed. This method computes the Tsallis entropy of edge and non-edge of 1ocal-image differently.based on the best Tsallis entropy of local image,a evaluation function is proposed.Based on the evaluation,the different structure of edge detecting is selected, the image edge information is enhanced,and avoids the edge missing.Experiment results show that, compared with the traditional edge detecting method,this method decreases the noise of infrared image as possible as it can and enhances image edge.