Tooth extraction itself is an invasive operation, and as long as it is an invasive operation there is a corresponding risk of infection clinically, mostly due to poor oral hygiene for the post-extraction period or inadequate application of antibiotics during the perioperative period of tooth extraction. In case of post-extraction infection, the first step is to check whether there is redness, swelling and pus spillage in the extraction wound. If there is obvious pus, a low incision can be considered to allow adequate drainage of the pus, and the pus can be taken for bacterial culture combined with drug sensitivity testing while incision and drainage are in progress. If the pathogenic bacteria can be determined, it will help a lot with the medication, if not, systemic antibiotics are recommended to control the systemic infection.