Enlarged axillary lymph nodes of breast cancer may be the metastasis of breast cancer combined with axillary lymph nodes, or it may be reactive hyperplasia. When this condition is found, puncture biopsy of axillary lymph nodes should be done in time. Lymphatic metastasis of breast cancer is mostly seen in axilla initially, and the cancer cells invade into axillary lymph nodes on the same side through lymphatic vessels of lateral margin of pectoralis major muscle, and the enlarged lymph nodes are hard, painless, can be pushed, and then increase in number, merge into a mass, and may even be adhered to the skin or deep tissues. There is also reactive hyperplasia of the lymph nodes, which is characterized by lymph node enlargement. In addition to the above cases, lymph node enlargement may also be caused by lymphoma or other systemic tumors, therefore, for this case, we should do the biopsy of lymph nodes as soon as possible to clarify the pathological results, and guide the next step of treatment according to the pathological results. It is recommended that the patient should go to a regular hospital as soon as possible and receive treatment according to the doctor’s instructions.