Localized breast cancer masses have to be removed, and certain safety margins have to be removed, so the breast defect is large. If the extent of the defect does not exceed 20%, the appearance of the breast can be met by certain sutures and certain displacement, or the appearance will not be greatly changed. Oncoplastic surgery is used to make breast surgery as aesthetic as possible through the principles and techniques of plastic surgery to the extent that the tumor is safely removed. If the volume removed in breast-conserving surgery is >50% or between 20% and 50%, oncoplastic surgery techniques must be used to achieve a more aesthetic surgical appearance through local volume replacement and volume displacement. If the defect is too large, the defect can also be filled by local axial flap transfer, such as a local flap of the latissimus dorsi muscle or a flap of tissue innervated by a tipped vessel in the lateral chest wall. Oncoplastic surgery techniques allow the appearance of the breast to be essentially the same after breast-conserving surgery.