Mammography is becoming more and more popular in the diagnosis of breast cancer, and the mammography camera is becoming more and more advanced, especially after the application of digital technology, the clarity of the camera is greatly improved, which is conducive to the detection of breast cancer and reduces the dose of radiation. However, mammography also has limitations, for example, it is not suitable for young patients because young women have denser breasts and it is difficult to detect small lesions; even a negative mammography test in a suitable population cannot completely exclude the diagnosis of breast cancer; therefore, it is not appropriate for some doctors to consider mammography as the gold standard for breast cancer diagnosis. In the diagnosis of breast cancer, mammography is necessary, but not absolute. The diagnosis of breast cancer mainly relies on comprehensive examinations: 1. Palpation: i.e. doctors check by touching with their hands, the accuracy of palpation by experienced doctors can reach 80%. 2. Ultrasound examination: the accuracy rate can also reach 80%. 3, is the mammography: the accuracy rate is also 80%. Each of the three methods has its own limitations, so the diagnosis of breast cancer emphasizes comprehensive examination, that is, the three examinations complement each other so that no diagnosis is missed. Mammography features of breast cancer Malignant tumors of the breast grow faster and often show internal necrosis and calcification, which can be easily detected by mammography. The calcification in breast cancer is mostly in the form of small sediment-like calcifications, often in dense clusters with uneven thickness and varying intensity. Some of the malignant breast tumors may appear as simple lumps on radiographs, while typical breast cancer may appear as round or round-like with lobulation, burr or haptic signs. Some malignant breast lesions may also show limited dense shadowing, nipple invagination, poor breast structure, ductal dilatation, and local structural disorders often coexist with microcalcifications and dense shadowing. The presence of calcifications with asterixis and structural disturbances should be differentiated from fat necrosis, and from sclerosing adenopathy in the form of microcalcifications alone.