An algorithmfor the automatic detection of infrared small sea target based on wavelet and fractal is proposed. Firstly ,the original image is decomposed to subimages. Secondly ,by computing the fractal parameter of the low frequency subim age and using the variety of fractal parameter in different texture images , we can confirm the position of skyline .Lastly ,considering infrared targets usually have high value of intensity ,we can find the target by carefully search near the skyline. Experiments show that this algorithm is effective to eliminate the clutters of clouds and offing ,and is suitable for the detection of remote infrared small target under the complicated background of sea and sky.