Breast cancer is a malignant tumor that seriously threatens the health of women, with an increasing incidence rate. The current main treatment methods include multidisciplinary diagnosis and treatment such as surgery, radiotherapy, chemotherapy, and endocrine therapy, among which surgery is the key. Postoperative care is also very important. Traditional breast surgery requires long-term placement of drainage tubes after the operation. However, long-term placement of drainage tubes increases the incidence of postoperative complications such as infection and delayed wound healing, prolongs hospital stays, increases economic burden, and also affects the aesthetic outcome. Our team has innovatively adopted the "reverse-sequence" endoscopic nipple-sparing-mastectomy with direct-to-implant breast reconstruction. This method is highly efficient and safe, with no incisions on the surface of the breast, reducing the risk of incision dehiscence and the probability of flap ischemia and necrosis. Based on this, our team proposes to appropriately relax the drainage criteria and remove the drainage tube earlier under the premise of ensuring the sterility of the effusion, and preliminary findings show that patients have better postoperative aesthetic outcomes, with a lower incidence of flap infection, ischemia, and necrosis than expected, and the degree of breast deformation caused by radiotherapy is also reduced. However, there is still controversy over the pros and cons of drainage criteria. Some scholars believe that strict drainage criteria can reduce the risk of infection and implant displacement, and plastic surgeons are more concerned about the impact of long-term tube placement on aesthetic outcomes and quality of life. Currently there is a lack of large sample, multicenter, randomized controlled studies to provide high - level evidence. Therefore, our team plans to conduct a national multicenter, open, randomized controlled study to compare the advantages and disadvantages of the two drainage methods under the premise of not reducing postoperative surgical and oncological safety, in order to explore the optimal timing for drain removal and improve patients' satisfaction with the reconstructed breast.