As with other diseases, early detection is a prerequisite to ensure a good prognosis for breast cancer. The first symptom of breast cancer is breast lump (nodule or mass), which may be accompanied by dimpling of breast skin (dimple sign), and in a few cases, nipple overflow and breast pain, and in some cases, breast redness and hardening. In some cases, there is redness and hardness of the breast. In early cases, there may be no clinical symptoms, so how can breast cancer be detected early? Active participation in breast cancer screening and regular breast examination is an effective method for early diagnosis. Self-examination: It is very important to strengthen the awareness of cancer prevention and regular and regular breast self-examination to detect breast abnormalities and visit breast specialists in time. It is recommended for adult women to perform self-breast examination 7~14 days after each menstrual period. Imaging examination: Mammography is one of the main means for early detection of breast cancer. Women over 40 years old should be examined once every 1~1.5 years, and for high-risk groups, it can be advanced to 35 years old. Ultrasound can detect small nodules under 1 cm that cannot be reached by palpation. It is sometimes more sensitive than X-ray and is especially suitable for young people with dense glandular tissue. Both types of imaging have their advantages and disadvantages, and they can complement each other. In contrast, breast magnetic resonance imaging can be used as a complementary test for a small number of patients. Breast ductoscopy: This test is suitable for patients with nipple overflow. Pathological diagnosis: Pathological diagnosis is the “gold standard” for breast cancer diagnosis. CNB is the most direct, simple, less invasive and highly confirmatory method, which has become the routine and standard examination method recommended by international breast cancer experts. The use of rapid frozen pathology biopsy for surgical excision has become less and less common.