Different flap surgical program, then the precautions are different: 1, free skin grafting, blood supply mainly from the trauma of the capillaries, granulation tissue, the main should be wrapped tightly, to avoid the flap move lead to necrosis; 2, with vascular tip of the local transfer flap, the blood supply mainly from the tip of the blood vessels, we should pay attention to keep the tip of the flap is not loose and not compressed, to avoid the tip of the distortion, to prevent the vascular compression and blockage of the necrosis caused by the necrosis; 3, with the vascular tip of the free skin flap grafting: we need to ensure that the anastomosis is well healed, to prevent thrombus, vascular spasms.