Abstract:Aiming at the specific challenges in UAV power inspection, such as the high proportion of small targets, the easy loss of fine crack features, and complex background interference in insulator defect detection, a lightweight detection model named YOLO-SCD is proposed based on an improved YOLOv11n architecture. The method enhances detection accuracy through multi-dimensional structural optimizations: a C3Star module based on star operation is designed to strengthen the backbone network’s ability to capture subtle defect features via implicit high-dimensional mapping; a context-aware attention fused CAA-HSFPN neck network is constructed to reinforce multi-scale feature fusion and suppress background interference; a decoupled enhanced DE-LSCD detection head is adopted, combining deformable convolution and an EMA attention mechanism to improve adaptability to geometrically distorted targets; and the Inner-WIoU loss function is introduced to optimize the bounding-box regression process. Experimental results on a self-built insulator defect dataset show that YOLO-SCD achieves a precision P of 89.79% and an mAP@0.5 of 87.06%, representing improvements of 2.72% and 2.47%, respectively, over the baseline YOLOv11n, while the parameter increase is only 0.37×10?, effectively balancing detection accuracy and model lightweightness, thereby meeting the practical requirements for high-efficiency and high-accuracy insulator defect detection in inspection engineering.