The accuracy and high efficiency of the foreign object debris (FOD) detection on the airport runway directly determines the safety of the civil aviation industry. In order to improve the positioning accuracy of airport runway foreign objects, this paper proposes a centroid localization method based on the combination of wavelet transform with the mathematical morphology algorithm. The algorithm firstly performed wavelet decomposition on the acquired target image, and the high-frequency part used multi-scale edge detection of wavelet transform and the wavelet threshold denoising, the low-frequency part used the morphological algorithm to perform morphological edge detection. And then the high-frequency and low-frequency foreign object images were fused. Finally, the method of centroid location was applied to determine the pixel coordinates of the foreign object. The experimental results show that the edge of the runway foreign object extracted by this algorithm is delicate and accurate in positioning, and can effectively identify foreign objects with similar background to the airport runway and be accurately located.