Breast-conserving surgery refers to the removal of only the breast gland, skin, subcutaneous tissue and axillary lymph nodes in the quadrant where the tumor is located. It is suitable for early stage breast cancer, single lesion, diameter ≤2cm, more than 2cm from the nipple, no local progressive symptoms, negative pathological examination of the cut edge and no suspicious calcification foci in other parts of the breast. Advantages of breast-conserving surgery: 1. The small excision area of breast-conserving surgery and the preservation of most of the breast can improve the patient’s postoperative quality of life, improve the function of the affected upper limb, and reduce surgical complications. The recurrence rate in the affected breast is basically the same as that of “traditional” surgery such as modified radical surgery. 3.After surgery, adjuvant radiotherapy and chemotherapy can achieve the same long-term survival rate as that of “traditional” surgery such as modified radical surgery. If recurrence occurs in the affected breast after breast-conserving surgery, remedial total mastectomy can be performed, and the survival rate can still be similar to that of modified radical surgery.