Aiming at the problem that the target in high-resolution SAR image is complex,has serious coherent speckle noise, and the gray level fluctuates violently leading to blurred edges of the target for accurate segmentation,a high-resolution SAR image segmentation algorithm based on Riesz fractional Derived (RFD) edge detection and pulse coupled neural network (PCNN) in fractional Fourier transform (FrFT) domain is proposed.The original image is processed by edge detection to retain better edge information,and then the image is segmented by the PCNN model.The coherent spots are further removed by morphology.The proposed algorithm is applied to high-resolution SAR image segmentation in different regions,and the experimental results show that it can effectively suppress the influence of speckle noise and gray boundary-blurring,and achieve an accurate segmentation effect.