The Nipple-sparing Mastectomy combined with Tissue Expander Implantation and Axillary Lymph Node Dissection with Lateral Mini-incision has been performed by our team since 2016，with more than 200 cases completed. This surgical method balances safety and aesthetics，improves surgical efficiency，and the therapeutic effect was satisfactory without significant complications. Firstly，a slightly curved arc incision is selected on the outside of the areola，extending no more than 6 cm in length. The breast skin flap is freed with an electrosurgical scalpel，and the posterior margin of the nipple is excised with a scalpel to check for cancer invasion by intraoperative frozen pathology. The breast gland is then excised from the surface of the pectoralis major，and the axillary lymphatic fatty tissue（Level Ⅰ andⅡ）is dissected using an ultrasonic scalpel. Subsequently，the tissue behind the pectoralis major is freed，and the lateral end of the pectoralis major rib is cut. After confirming that there is no cancerous infiltration on the cut margin behind the nipple，the tissue expander is placed using the dual-plane method to construct the cavity. Finally，two drainage tubes are left in place，and the incision is sutured layer by layer.