Ulcers under the tongue should be removed in time if there are local irritants. For example, if there is a stump or a crown or a bad restoration in the corresponding area, or if there is a habit of eating spicy and irritating food for a long time, or if there is a bad habit of biting the lip or the tongue, then all of them should be removed in time. It is also recommended to minimize smoking and not to drink strong alcohol. And the ulcers under the tongue can be used to promote the healing of the drug, commonly used are tretinoin ointment, you can also use the dexamethasone drug patch. You can also use spray medications, commonly used are watermelon cream spray, open throat sword spray, stomatitis spray and so on. And it is recommended to use mouthwash to maintain oral hygiene, can inhibit the infection of bacteria in the mouth, commonly used are cotrimoxazole gargle, rehabilitation of new liquid, or you can also use cotrimoxazole gargle, which can promote the healing of the ulcer. If the ulcers are deep and large, you can use dexamethasone or prednisolone suspension for local submucosal injection, usually need to go to a professional stomatology department for consultation.