The number of breast cancer incidence is increasing rapidly and now accounts for the first place of malignant tumor incidence among women in China. With the advancement of science, the detection of early breast cancer is increasing, and the multidisciplinary collaboration and progress in treatment have led to a significant improvement in the prognosis of breast cancer. The cause of breast cancer is still unknown and is associated with a variety of tumorigenic factors, especially estrogenic changes in the body. These risk factors include early menarche (≤12 years old), late marriage and first pregnancy (≥35 years old), having a first-degree relative such as a mother or sister with breast cancer, having had breast cancer before, or having a benign breast lesion. Self-examination of the breast should be done monthly, and it is appropriate to do it about 1 week after menstruation. If a lump is found in the breast, you should immediately consult a doctor for examination. It is recommended to have one to two ultrasound examinations of the breast each year above the age of 30, and one mammogram each year above the age of 40. Ultrasound can detect small, hard-to-reach lumps, which can be diagnosed early through ultrasound-guided hollow-core needle aspiration or minimally invasive surgical biopsy by McMurdo. Mammography can reveal some lesions without lumps, such as localized distortion of the breast and tiny dense calcified foci, which can also be diagnosed at an earlier stage through localized puncture or surgical biopsy. Later breast cancer mainly presents with localized lumps that can be palpated, hard and less mobile, often accompanied by enlarged axillary lymph nodes. Apart from the clinical signs of palpable lumps, ultrasound, mammogram and sometimes MRI are needed to provide information, but the diagnosis must be confirmed by histological examination (also known as biopsy). The treatment of breast cancer may vary according to different stages, biological characteristics and types of tumors, and is a comprehensive treatment process, including surgery, chemotherapy, radiotherapy, endocrine therapy and molecular targeted therapy, which requires multidisciplinary collaboration. Surgery is still one of the main means of treatment, and real surgical progress is just over 100 years old. Surgical modalities include radical surgery, modified radical surgery, breast-conserving surgery and additional axillary anterior lymph node biopsy. With advances in radiotherapy, extended radical surgery has tended to be eliminated, radical surgery is rarely used, modified radical surgery is gradually decreasing, and breast-conserving surgery will increasingly emerge. Modified radical surgery preserves the pectoralis major and minor muscles, so that the tumor can be satisfactorily removed and the function of the limbs can be preserved and the thorax will not be seriously disfigured. Breast-conserving surgery preserves the breast, and the shape of the breast does not change much after surgery, which can enhance the patient’s self-confidence. However, with either mastectomy or breast-conserving surgery, there is an increased chance of upper limb edema after axillary lymph node clearance, and the resulting function of the upper limb may be severely affected and difficult to manage. If there is no metastasis, axillary lymph node removal can be avoided and the chance of upper limb edema can be reduced. Although surgery can cure some breast cancers with early stage and weak invasiveness, and the existing diagnostic tests cannot detect the presence of micro-metastases, most breast cancers are not early stage when diagnosed, and studies have shown that many breast cancers have micro-metastases, and these tumor cells are in the body enough to cause recurrent metastases and make treatment failure. Therefore, most breast cancers require adjuvant therapy after surgery. The main adjuvant treatment is chemotherapy and endocrine therapy, chemotherapy is the use of drugs to destroy the remaining cancer cells in the body, but of course not all breast cancers need chemotherapy. For luminalB, HER-2 over-expressed and triple negative breast cancer, chemotherapy is required. Adjuvant chemotherapy includes preoperative chemotherapy (neoadjuvant chemotherapy) and postoperative adjuvant chemotherapy. Neoadjuvant chemotherapy is needed if the breast cancer is too large for surgery. The purpose of neoadjuvant chemotherapy is to improve the surgical resection rate and breast-conserving surgery rate. The purpose of post-operative adjuvant chemotherapy is to eliminate residual tumor cells and micrometastases in the body, reduce recurrence and metastasis, and improve the cure rate. The common side effects of chemotherapy include nausea, vomiting, hair loss, bone marrow suppression, etc. Symptomatic treatment is effective. Endocrine therapy and chemotherapy are systemic treatments for breast cancer. Each patient is tested for estrogen receptor (ER) and progesterone receptor (PR) after tumor removal, and if ER and/or PR are positive, endocrine therapy is effective. Tamoxifen or toremifene can be used for premenopausal endocrine therapy, and postmenopausal patients can choose aromatase inhibitors or tamoxifen. The side effects of endocrine therapy are less severe proportionally compared to chemotherapy and are more acceptable to patients. Side effects include endometrial hyperplasia, thromboembolic events, fatty liver and bone calcium loss. Radiotherapy is a local treatment. If there is metastasis in axillary lymph nodes or tumor diameter ≥5cm on surgical specimen is an indication for radiotherapy. With the improvement of radiotherapy technology, radiation pneumonia and heart damage are rarely occurring now. Targeted therapy is a new advancement in breast cancer treatment, which can further reduce metastatic recurrence based on chemotherapy and endocrine therapy. Immunohistochemical examination should be performed in every case of tumor specimen resection, and if Her-2(3+) or FISH test is positive, targeted therapy with trastuzumab is recommended. Cardiac function needs to be monitored during targeted therapy and the use of anthracycline chemotherapy drugs. Through standardized treatment, the chance of breast cancer recurrence and metastasis is significantly reduced, but still a small percentage will recur. The average 5-year overall survival rate of breast cancer is about 80%, and there is still a way to treat recurrent breast cancer. Treatment is based on systemic therapy, and different chemotherapy regimens and endocrine drugs can be chosen. The choice of targeted therapy is similar to the previous one, and recurrent metastasis specimens can be retaken for examination. In conclusion, breast cancer treatment is one of the few solid tumors with good therapeutic effect and treatment must be adhered to and standardized.