A particularly dry mouth is essentially caused by a decrease in the secretion function of the submandibular glands, parotid glands, sublingual glands and other glands in the oral cavity, which can lead to a decrease in saliva secretion and a loss of saliva moistening of the oral mucosa, resulting in a dry mouth. It is necessary to pay attention to oral hygiene, drink more water or use artificial saliva to moisten the mouth, and try to eat less food with high sugar content, such as honey, ice cream and ice-cream. The lack of saliva in the mouth will increase the probability of dental caries. It is necessary to go to the hospital stomatology department to check whether there is mumps or chronic submandibular adenitis, and the possibility of salivary stone disease development. If it is accompanied by dry mouth, dry eyes and rheumatic immune diseases, it is necessary to go to the rheumatology department to exclude Schelgren’s syndrome.