It is also a common complication after breast cancer surgery. Because skin graft necrosis and delayed healing may affect the follow-up treatment. Radical mastectomy often needs to remove more skin, large-scale skin flap separation, thin or uneven skin flap peeling, which will destroy the capillaries in the dermis and affect the blood supply of the skin flap after operation. Or the tension of the flap is too high during suture, and it will also cause ischemic necrosis of the flap when the wound accumulates fluid after operation; Sometimes, due to improper operation of electrosurgical excision procedure, local skin burns or vascular coagulation embolism are caused, and it is also easy to cause skin flap necrosis. Skin flap necrosis usually occurs 24 hours after operation. Ischemic skin turns pale and gradually turns blue-purple, and there are small blisters on the edema surface. After 3 ~ 7 days, the boundary of necrotic area gradually became clear, and black hard scab gradually appeared on the skin.