Breast cancer is the most common malignant tumor in women, and the incidence rate ranks the first among female malignant tumors, which seriously threatens the physical and mental health of women. Axillary lymph node grading is an important factor in determining the diagnosis, treatment and prognosis of early stage breast cancer, and depending on the status of axillary lymph nodes, clinicians can develop treatment strategies for patients. For many years, the main method to determine the status of axillary lymph nodes in clinical practice has relied on axillary lymph node dissection. However, with the development of diagnostic imaging in recent years, the early diagnosis rate of breast cancer has been increasing, and 50% to 70% of breast cancer patients do not have axillary lymph node metastasis, so axillary lymph node dissection for these patients is a kind of overtreatment, which not only will not significantly improve their survival outcome, but also will cause the occurrence of postoperative syndromes such as edema and numbness in the upper limbs, which will seriously affect the quality of life of patients. . In order to both accurately assess the status of the axillary lymph nodes and minimize the scope of surgery, an alternative method to axillary lymph node dissection, sentinel lymph node biopsy, has gradually been explored clinically. Sentinel lymph nodes refer to the lymph node or lymph nodes that are first reached by tumor cells that have metastasized through lymphatic conduits. We routinely perform sentinel lymph node biopsy intraoperatively, freeze the sentinel lymph nodes intraoperatively and perform axillary lymph node dissection if the sentinel lymph nodes have cancer metastasis, and avoid axillary lymph node dissection if the sentinel lymph nodes do not have cancer metastasis. It significantly reduces surgical complications, improves quality of life, and reduces medical costs.