Abstract: For that UAV reconnoiters and monitors ship targets in the designated area when there is no e ective pre sample image accumulation, an infrared ship target detection method based on multi-resolution di erential filtering is designed. In this method, the input images are filtered in di erent resolutions, and then detection results are obtained by combining the filtering results with the selective search algorithm. In the experiment, 139 images are selected as the test image data set, and the multi-resolution di erence filtering method is used to detect infrared ship targets in it. The average detection accuracy is 89.378 %, which is 8.445% higher than that of the HOG + SVM method.