Breast cancer is currently the first malignant tumor to develop in women. Early detection can reduce the incidence and mortality of breast cancer (in common parlance, but this is problematic from a professional and statistical perspective), but too much or excessive screening can also cause harm that cannot be ignored. Mammography uses soft X-rays to project light onto breast tissue and then develops and fixes the image through film sensitization. The advantages of mammography are that it is non-invasive, easy to perform, and has high resolution and reproducibility, and the images can be compared before and after, but it is limited by age and size. Mammography has a sensitivity of 82% to 89% and a specificity of 87% to 94% for the diagnosis of breast cancer, and was once the routine choice for breast cancer screening and breast disease examination. However, decades of use have shown that in some highly specialized hospitals/medical centers mammography does not have a significant advantage over ultrasound in terms of accuracy, and the two actually constitute a complementary relationship. The American Cancer Society ACS updated its guidelines for breast screening in 2015: 1. delayed the age of screening onset from 40 to 45 years; 2. recommended annual radiographic (mammography) screening from 45-54 years of age, every two years from 55 years of age, and continued x-ray screening is still recommended for healthy women over 70 years of age (life expectancy of 10 years or more); 3. not recommended for women at average risk at any age group for breast cancer prevention through routine clinical screening. Screening needs to grasp the applicable population and applicable methods, that is, what kind of screening methods are used for what kind of population; while preoperative ancillary diagnosis is necessary, including for clear diagnosis, lesion localization, and feasibility assessment before breast-conserving surgery.