Isotropy edge detection filters for synthetic aperture radar (SAR) images, such as crater-shaped window (CSW), cannot keep both high edge resolution and good speckle suppression ability at the same time. In this letter, an edge detector-combined CSW and robust inhibition-augmented curvilinear operator (RUSTICO) has been proposed. First, the preliminary edge strength map (ESM) is calculated by using CSW. Second, the RUSTICO is applied to suppress the influence of speckle and obtain the improved ESM (IESM). Moreover, by using nonmaximum suppression and hysteresis thresholding on IESM, the one-pixel-wide edges are acquired. Finally, the missing edges at intersection areas are extracted by the linking method. The experimental results on simulated and real SAR images demonstrate that the proposed edge detector can yield accurate and integrated edge map.