For offshore oil pollution cleaning, manual cleaning methods are costly and harmful, especially unable to adapt to the complex sea conditions under severe weather and the toxic oil pollution environment prone to fire. For this reason, the introduction of multiple unmanned surface vehicles loaded with oil pollution cleaning equipment has become a necessary way. In order to solve the efficient cooperation between multiple unmanned surface vehicles, a custom right-angle path planning algorithm is proposed. First, perform edge contour extraction, convex hull point search and clustering on a given oily image. Secondly, determine the target convex hull point and its assignment with multiple unmanned surface vehicles; then, through the custom right-angle method path planning, a collision-free path from the current position to the target convex hull point is planned. Finally, a comparative simulation experiment was carried out to verify that the custom right-angle path planning algorithm has fewer turning points in the path, easy to track by an unmanned surface vehicle, and more feasible and superior.