Mammography is becoming more and more popular in the diagnosis of breast cancer, and some doctors even regard this test as the gold standard for breast cancer diagnosis. In fact, this understanding is one-sided. In the diagnosis of breast cancer, mammography is necessary, but not absolute, and it is not appropriate to consider it as the “gold standard”. At present, the diagnosis of breast cancer mainly relies on three aspects: first, manual diagnosis. Firstly, manual diagnosis, which is the examination by touching the breast by hand, can reach 80% accuracy rate. Secondly, ultrasound examination. The accuracy rate is also up to 80%. The third is mammography. The accuracy rate is also 80%. However, since each of the three methods has its own limitations, the diagnosis of breast cancer emphasizes comprehensive examination, that is, the three examinations complement each other so as not to miss the diagnosis. Although mammography is becoming more and more advanced, especially with the use of digital technology, the clarity of the camera is greatly improved, but this does not guarantee that it is 100% accurate in diagnosing breast cancer. Ultrasound can detect lesions that cannot be detected by f-target. In clinical practice, experienced physicians can sometimes confirm the diagnosis for patients by hand examination at a very low cost. However, patients are often unsure of the diagnosis and request other tests; many other patients are unsure of the diagnosis at one hospital and prefer to go to multiple hospitals for repeated tests to confirm the diagnosis. The patient’s feelings are understandable, but mammography is now more common in large and medium-sized cities across the country, which can easily lead to an increase in the number of tests patients receive. But mammograms and ultrasounds are not harmful to the body and should not be done more often, and they are more expensive. For the doctor, if the patient has already had a mammogram recently, it is not advisable to do it again.