After tooth extraction, it can be divided into primary and secondary. Primary bleeding is bleeding at the time and not stopped after tooth extraction; secondary bleeding is bleeding that has been stopped at the time of tooth extraction but occurs later due to other reasons; local examination often shows a blood clot that is higher than the alveolar fossa, loose and oozing blood; apply cotton ball to remove part of the blood clot that is higher than the alveolar fossa, and then use gauze and cotton roll to compress to stop bleeding. Usually, if the gums on both sides can be sutured horizontally, so that the mucoperiosteal flaps on both sides are tense, which helps to stop the bleeding, and the suture is compressed for 5-10 minutes, if the bleeding still cannot be stopped, iodoform sponge can be implanted in the upper part of the alveolar fossa. The gauze is removed at one week and replaced by a shorter one placed loosely. After several times of replacement, the fossa will gradually heal with the growth of granulation tissue.