Stage IIIa breast cancer is almost impossible to be cured by itself, and needs to be treated by surgical excision, radiotherapy and targeted therapy. Breast cancer is a common malignant tumor, and the occurrence of the disease is related to many factors such as heredity and hormone level. Stage IIIa represents the absence of primary tumor size larger than 5cm; 4-9 axillary lymph nodes metastasis, or positive ipsilateral internal breast lymph nodes without axillary lymph node metastasis in imaging examination; and the absence of distant metastasis, etc. This period belongs to the middle and late stage of the disease. This period belongs to the middle and late stage of the disease, which needs to be treated by surgery, radiotherapy, targeted therapy and other methods in conjunction with the disease, and after active treatment, a five-year survival rate of about 50% can be obtained. On the contrary, the disease usually develops to the advanced stage quickly, and distant metastasis occurs, which seriously jeopardizes the patient’s life.