Breast ultrasound and mammography are different in principle and in their adaptations, so it is not possible to generalize which one is more accurate, but rather to analyze each case on its own merits. Breast color ultrasound is more accurate in diagnosing the number, size and location of breast nodules. Moreover, breast color ultrasound is a non-invasive examination, no radiation, easy to operate, and not expensive, so the popularity of this examination is higher. Mammography is more accurate in diagnosing the benign or malignant nature of known breast nodules. This is because mammograms are more penetrating. However, the test is radioactive. It has a unique and irreplaceable advantage in the early detection of breast cancer. Both breast ultrasound and mammography have their own advantages, and it is recommended that patients go to a regular hospital and choose a reasonable examination method under the guidance of the doctor.