Breast cancer chemotherapy followed by surgery may be stage II or III as well as partial stage I. Preoperative chemotherapy, also known as neoadjuvant chemotherapy, is mostly used in locally advanced cases to shrink the tumor, improve the chances of surgical success and detect tumor sensitivity to drugs. Neoadjuvant chemotherapy may be required for stage II or stage III breast cancer, and some pathological types of stage I also require neoadjuvant chemotherapy. At present, anthracycline combined with paclitaxel combination chemotherapy regimen is commonly used for cases with poorly differentiated tumors and late staging, and paclitaxel-based regimen can be considered for cases with better differentiated tumors and earlier staging, and the patient should be free of obvious myelosuppression and abnormalities in liver function before chemotherapy. Digestive tract reaction and allergic reaction may occur during the use of drugs, and those who apply adriamycin should pay attention to cardiotoxicity. Other more effective chemotherapeutic drugs include vincristine and platinum, etc. Invasive breast cancer with axillary lymph node metastasis is an indication for the application of adjuvant chemotherapy. It is generally believed that those with negative axillary lymph nodes and high-risk factors for recurrence, such as primary tumor diameter greater than 2cm, poor histological grade, negative estrogen and progesterone receptors, and overexpression of oncogene epidermal growth factor receptor 2, are suitable for the application of postoperative adjuvant chemotherapy. It is recommended that patients should consult the doctor in time, and should not treat the tumor blindly on their own, so as to avoid delaying the condition.