In recent years,the bridge construction in China has developed unprecedentedly,and the problem of bridge safety operation and maintenance has become more and more prominent.In this paper,we propose a crack detection model YOLOv8-BC based on YOLOv8,which adopts GhostConv's improved structure of HGNetv2 to replace the backbone net-work of YOLOv8,to realize the model's lightweight;introduces the deformable attention mechanism DAttention,to obtain more spatial information;and uses the auxiliary edge-based inner-iou loss function based on auxiliary edges instead of CIOU loss function to improve the generalization ability and detec-tion accuracy of the model.Experiments on the self-con-structed dataset show that the YOLOv8-BC model achieves an accuracy of 95.3%and the mAP50 reaches 95.9%,which is improved by 2.3%and 2.0%,respectively,compared with the YOLOv8s model,while the number of parameters is reduced by 15.3%.This indicates that the YOLOv8-BC model can detect bridge cracks in complex environments more efficiently,which provides important ideas and technical support for in-dustrial inspection.