Breast cancer surgery usually does not involve internal organs, but is done outside the chest wall, which is relatively less invasive and risky, and is generally not considered major surgery. The traditional radical mastectomy requires removal of the entire mammary gland plus axillary lymph node dissection, while the modified radical surgery now preserves the pectoralis major and pectoralis minor muscles. In early stage or if the patient is young and has the will to preserve the breast, breast-conserving surgery is also an option, where the nipple and areola are preserved and only the breast tissue is removed, including the tumor site, and the postoperative treatment is combined with radiotherapy and chemotherapy. Breast cancer is a systemic disease, surgery is only the first step, and post-operative comprehensive treatment is also very important.