The most accurate results of breast ultrasound are obtained about 7 days after a woman’s menstruation. Breast ultrasound is mainly used to diagnose breast diseases through ultrasonic reflection. Ultrasound examination of the breast can observe the size, shape, internal structure, distribution of internal blood vessels and blood flow of breast lumps, and clearly show whether the breast and surrounding tissues are diseased, which can provide important reference for clinicians to make disease diagnosis. Since estrogen is low when a woman is 7 days clean, the effect of estrogen on the breast is minimal at this time, and the breast tissue is softer than soft, and the breast glands are weaker, breast tissue lesions or abnormalities are most easily detected. When women experience breast discomfort, it is recommended that they go to the breast surgery department of a regular hospital for breast ultrasound examination in a timely manner. Before the examination, patients should pay attention to keep their skin clean, fully expose their breasts and armpits during the examination, be fully prepared psychologically, relax and actively cooperate with the examination.