Abstract: This article reports a case of a 30-year-old lactating breast cancer (LBC) patient with macromastia, presenting with multifocal tumors in the left breast and axillary lymph node metastasis. After neoadjuvant chemotherapy, the patient underwent radical mastectomy of the left breast combined with autologous reconstruction using a transverse rectus abdominis myocutaneous (TRAM) flap and reduction mammoplasty of the contralateral breast. The postoperative pathology showed a pathological complete response (pCR), with good blood supply to the flap and no severe complications. This case is the first to apply the integrated strategy of "mastectomy-TRAM reconstruction-reduction mammoplasty" in a lactating breast cancer patient with macromastia, providing an innovative individualized treatment option that balances tumor safety and aesthetic restoration.