In view of the most basic sunny days, night and dense fog weather conditions, corresponding filtering of ship images and a scheme for positioning suspicious ships are designed. Gaussian filtering, Laplace image enhancement, and image dehazing are applied to the three different models, which provide better image quality for further ship positioning. The contour feature of the ship is extracted and the number of feature points is reduced by the RDP (Ribosomal Database Project) algorithm. The location of the ship is drawn and calibrated according to the feature extracted. The position of the central point can be extracted. The results show that the gray level of the image is low in the night mode, and the scheme proposed helps to improve the image contrast. The Retinex algorithm provides a feasible scheme for image dehazing. Feature extraction for ship positioning also has a good practical effect.