The incidence of breast cancer has increased dramatically in the 21st century, posing a challenge to medical science. Therefore, early diagnosis has been of great concern. Mammography has been used in clinical practice for half a century and is one of the most mature imaging methods for breast disease. High-frequency molybdenum-palladium camera X-ray machine has high resolution, good contrast, and can clearly display tiny lumps, vascular distribution and small calcification points, and the patient receives less radiation, less damage to the body, no pain, large irradiation range, can reveal the posterior space of the breast and the axillary area, and can dynamically observe the changes of breast hyperplasia and the effect of treatment, so it is the first choice for early breast cancer diagnosis. Ultrasound has been used to diagnose breast diseases for nearly 50 years. Ultrasound examination is not only painless, non-invasive and non-radioactive, but also simple and easy to perform, and the suspected lesion area can be repeatedly detected for comparison and follow-up, so it is a common method for clinical diagnosis of breast diseases. The breast is located on the surface of the body and has a thin anterior and posterior diameter, which makes it easy to apply a high-resolution high-frequency probe for examination. Ultrasound diagnosis is especially suitable for identifying cystic or substantive tumors, while the accuracy rate of identifying the benignity and malignancy of substantive tumors is generally between 85% and 90%. Breast ductal endoscopy is a new method developed since the 1990s to examine lesions in the breast ducts. An endoscope with an internal diameter of 0.4 mm or 0.75 mm is inserted through the opening of the overflowing duct and the endoscopic display is used to observe the situation in the ducts while probing the end of the milk ducts as far as the fifth or sixth branch of the milk duct. The entire procedure takes about 10 to 15 minutes and is painless or uncomfortable for the patient. The images observed can be recorded by video or photographic recording. Ductal carcinoma, intraductal papilloma, and ductal inflammation each have their own characteristic endoscopic appearance and can be diagnosed accordingly. Another role of endoscopy is to mark the surface skin of the detected lesions for accurate localization of the surgical biopsy. In addition, a biopsy of the lesion can be performed under endoscopic guidance to obtain a pathologic confirmation of the diagnosis. It is suitable for spontaneous nipple overflow, single duct nipple overflow, bloody nipple overflow and examination of lesions in the breast ducts and preoperative localization of lesions in the ducts.