The white mucous membrane inside the mouth, need to be dealt with according to the different causes of this symptom, common causes include external stimulation, oral white spots, snow mouth disease, oral lichen planus, etc. 1, external stimulation: after exposure to a large amount of salt or vinegar and other acidic substances, will lead to irritating changes inside the mouth, manifested as white mucous membrane, generally do not worry too much, with the passage of time the symptoms can be self 2, oral white spots: refers to the white patches occurring in the oral mucosa, including plaque, granular, crumpled paper, etc.. If diagnosed, it is necessary to remove the stimulating factors, such as quit smoking and alcohol, eat less hot and spicy food, and remove the residual roots and crowns of teeth, etc. It can be observed for 1-3 months, and if the lesion does not disappear, biopsy examination should be performed. At the same time, local application of retinoic acid ointment or cod liver oil can be used, and oral retinoic acid drugs, such as vitamin capsules, can be taken. If the symptoms are serious, surgery, freezing, laser, microwave and other methods can be used; 3, snow mouth disease: also known as thrush, is an inflammation of the oral mucosa caused by Candida infection, mostly seen in newborns, malnourished infants or children with long-term application of antibiotics. The main manifestation is the appearance of curd-like white film or white spots on the cheek mucosa, inner lips and palate, etc. After wiping hard, it is easy to cause mucosal bleeding, and there are no obvious symptoms in mild cases, but in severe cases, the oral mucosa looks like a thick layer of white film, and the surrounding area is congested and edematous and painful. At this time, parents can use sterile cotton swabs dipped in baking soda water to scrub the affected area for the child under the guidance of a professional doctor, paying attention to gentle movements to avoid damaging the affected mucosa and causing infection. If the condition is serious, you can follow medical advice to use mycobacterial tablets, fluconazole and other drugs; 4, oral lichen planus: is a chronic superficial inflammation of the skin – mucosal keratinization abnormal disease, clinical manifestations to white stripes, white plaques. At this time, patients should adjust the mental and psychological state, and use certain drugs for treatment, such as common prednisone, retinoic acid ointment, etc. For patients suspected of having vitamin deficiency, they should be supplemented in appropriate amounts. In daily life, patients should pay attention to keep their oral hygiene clean, rinse with mouthwash; pay attention to drink a lot of water, avoid spicy and stimulating food, and eat more vitamin-rich fruits and vegetables.