In this paper,a method for detecting infrared warship target in the complex background of sea-sky based on SUSAN detection and segmentation algorithm using the mean of image rows and columns.First,a simple model of warship contour was built.And the ROI can be decided subsequently,combine with SUSAN detection.Besides,the model of warship contour can control the size of the ROI in a way.Then,an improved segmentation algorithm based on the mean of image rows and columns was proposed.After the image segmentation,ship target was extracted.The experimental results show that the proposed algorithm is successful and can extract the infrared warship target.