Black blisters in the mucosa of the mouth are most likely caused by eating spicy, irritating or particularly hot foods that cause blood blisters in the mucosa. Hard objects such as fish spikes scraping into the mucosa can also cause blood blisters. Black blood blisters in the mouth can be self-absorbed if the area is not large, but it is important to avoid spicy, stimulating and overheated foods in the diet, and to focus on warm, cool and soft foods. If the area of the blisters is very large and the foreign body feeling in the mouth is strong and affects speech and eating, the patient should not pick the blisters by himself, which will lead to infection of the mucous membrane, and should go to the hospital and pick the blisters under strict sterilization of the doctor to discharge the pus and blood. At the same time, it is recommended to use mouthwash with anti-inflammatory function to prevent infection, such as concentrated tinidazole gargle, you can also gargle with rehabilitative new liquid, rehabilitative new liquid is conducive to the healing of mucosal trauma.