Possible reasons for wound not healing after gum cancer surgery include necrosis of transplanted skin flap, poor oral hygiene, lack of nutrition, etc. The details are as follows. 1. Necrosis of grafted skin flap: some patients with gum cancer need to undergo skin flap transplantation, if the grafted skin flap appears to be swollen, bleeding, decreased temperature and darkened color after operation, necrosis of grafted skin flap may have occurred and the wound can not be healed normally. 2. Poor oral hygiene: the self-cleaning effect of oral cavity is reduced after gum cancer surgery, secretions in oral cavity are retained, which may affect wound healing if not cleaned in time. 3. Lack of nutrition: after surgery, it is usually necessary to supplement liquid food with high protein, high calories and high vitamins, and lack of nutrition will affect the normal healing of wounds. There may be other reasons why the wound does not heal after gum cancer surgery, so it is recommended to go to the hospital in time to receive regular treatment as soon as possible.