Nipple discharge is a common symptom in women with breast disease, accounting for about 5% to 10% of routine mammography patients. A variety of benign and malignant lesions of the breast can have nipple discharge, and the nature, location and extent of the lesion are difficult to determine clinically. 1.Selective molybdenum ductography The injection of 76% pantopamine into the diseased ducts and radiography is of great diagnostic value for nipple overflow disease, especially for those without masses on physical examination or negative for other examinations, the branching pattern of the diseased duct system can be observed and the site, nature and extent of the lesion can be clarified. The addition of stain to the contrast agent can be used not only to reconfirm the diseased milk ducts preoperatively, but also to guide the boundaries of surgical excision to ensure that the diseased milk duct system is accurately and completely excised. 2.Magnetic resonance mammography Three-dimensional imaging and CT mammography three-dimensional imaging can provide three-dimensional localization of diseased milk ducts and lesions, but the technology is not yet mature and not many clinical applications are available. 3.Mammary ductoscopy is a diagnostic method to observe the lumen and wall of the breast ducts through ultra-fine optical fiber. The commonly used mirrors are 0.4mm, 0.7mm and 0.9mm in diameter, and can observe up to class III ducts. The diagnosis of nipple overflow disease is accurately localized and characterized. The benefits of breast ductoscopy include: ① clear indication for surgery, avoiding unnecessary surgery for normal ducts with overflow or duct dilatation; ② clarifying the site and scope of surgery, improving accuracy and avoiding unnecessary wide excision; ③ taking biopsy of suspicious lesions, providing conditions for early diagnosis of breast cancer; ④ for ductitis and periductitis, irrigation treatment is feasible. The irrigation fluid can also be used for exfoliative cytology and tumor marker determination. Through ductoscopy, surgeons have been able to solve the problem of nipple overflow that has been troubled.