In industrial manufacturing, it is difficult to obtain defective samples and the defects are in diverse forms. Anomaly detection, which only trains positive samples, is being increasingly applied to defect detection on product surfaces. Anomaly detection generally determines whether the product has defects by evaluating the anomaly score of the product image, while unable to describe the locations of the defects. The latest anomaly segmentation method has been improved, but the segmentation of the defective area is not accurate enough. Based on the anomaly detection method, normalization flow was employed to judge whether the product surface was defective, and multi-scale feature fusion and alignment were adopted to initially locate the defects. Combined with the gradient and maximum information entropy, the watershed algorithm was used to optimize the initial positioning results to obtain the defect segmentation mask. The detection and segmentation results on the three surface defect datasets of Lisheng Board, KolektorSDD, and AITEX are superior to other similar methods. In addition, good detection and segmentation accuracy can also be achieved on few-shots.