Measures to prevent flap necrosis after breast cancer surgery are as follows: 1. Avoid over-tightening the dressing, because tighter dressing can easily cause poor blood flow and lead to tissue necrosis; 2. Pay attention to keeping the drainage smooth, because poor drainage and long-term accumulation of fluid can easily lead to flap necrosis; 3. Choose the right time to remove the tube, if there is more fluid, you should not remove the tube, because after removing the tube, the fluid will flow out and need to reposition the tube to drain; 4. Enhance nutrition to speed up wound healing and flap recovery; 5. Pay attention to preventing infection and keeping the wound clean, because once infected, the rate of flap necrosis will increase.