The second stage suture is because the wound is very dirty inside, the pollution is very heavy, or the edges of the wound are red and swollen, the inflammation is particularly obvious, and even there is pus and other flow out, this time is not able to do the first stage suture, because the wound also grows badly after the suture, and also the infection will appear again, also need to remove the suture to change the medicine thoroughly. Therefore, for such a wound, it should be debrided first, rinsed repeatedly with hydrogen peroxide saline, and also the internal necrotic tissue needs to be removed, and depending on the exudation of the wound, the medication may have to be changed 2 times or 3 times a day. When the internal exudate of the wound is significantly reduced and fresh granulation tissue is generated around it, the wound is re-sutured, which is a second-stage suture. After the second-stage suture, the wound will take longer to heal and the scar will be very obvious after healing.