Sentinel lymph node biopsy (SLNB) is a new technique that emerged in the 1990s in surgical oncology and is a revolution in the surgical management of breast cancer. The purpose of SLNB is to remove the sentinel lymph nodes and to find out whether the axillary lymph nodes are metastatic or not through pathological histology, cytology and molecular biology diagnosis. By detecting sentinel lymph nodes, surgical staging of axillary lymph nodes and understanding the status of axillary lymph nodes in breast cancer is the basis for determining a comprehensive treatment plan. If there is no axillary lymph node metastasis, axillary lymph node dissection can be dispensed with, preserving the patient’s ability to work to the greatest extent and reducing the incidence of upper limb lymphedema after surgery. SLNB for breast cancer is suitable for patients with no clear metastasis in the axillary lymph nodes on clinical examination. It is controversial whether SLNB should be performed in patients with prophylactic mastectomy, history of ipsilateral axillary surgery, intraductal carcinoma, and clinically suspicious axillary lymph node enlargement. Inflammatory breast cancer and clinically stage N2 axillary lymph nodes are contraindications to SLNB.