Advantages: Ultrasound is painless to the patient, no radiological damage, can be performed repeatedly for a short period of time, and is suitable for any age and any physiological period of women, including pregnancy and lactation; no special preparation is usually required for the patient before the examination, the operation is relatively simple, there are no blind spots, and ultrasound can show areas that cannot be photographed by mammography, such as the edges of the breast, small dysplastic breasts or chest wall masses. Ultrasound has good resolution of soft tissues and can clearly show all layers of the breast and chest wall, so that the anatomical site and level of the lesion can be determined, breast masses and chest wall masses can be identified, and small masses of several millimeters can be detected. Ultrasound can be useful in determining the presence or absence of masses in dense breasts that are difficult to visualize with mammography. Disadvantages: Although ultrasound is very sensitive to calcified foci in hypoechoic masses, it is difficult to detect small calcified foci and burr-like changes easily detected by mammography when no mass is present or when the mass image is not obvious; solid breast masses, whether benign or malignant, are mostly hypoechoic, and most masses smaller than 10 mm lack specificity in their sonograms, and the blood flow signal is not obvious. It is still difficult to diagnose the benignity and malignancy of small masses by ultrasound. The fat or subcutaneous fat in the gland is nodular and hypoechoic, which is sometimes not easily distinguished from the lesion; for parasternal lymph node metastasis, it is difficult to show due to the obscuration of the sternum and ribs; due to the heterogeneity of the glandular structure and the relatively large area of the examined breast, it is easy to miss smaller lesions. The frequency of ultrasound instruments and probes directly affects the image quality and the display of lesions, and the examiner’s knowledge of breast diseases, operating skills and thinking and analyzing ability have a greater impact on the diagnostic accuracy.