In the process of chemotherapy, after eating stimulating, spicy and overheated food often cause irritation to the oral mucosa, so the oral mucosa is red, swollen and painful thus causing oral mucositis, and it also causes thirst, secondary damage and other oral series of problems appear. Prevention countermeasures: to keep the mouth clean, in order to avoid damage to the oral mucosa, it is recommended to apply a softer-bristled toothbrush, and to avoid rough brushing habits, to develop the habit of brushing and rinsing after meals, before bed, early in the day, and the cleanliness of the tongue is also very important. Countermeasures for stomatitis: You should often observe the state of the mucous membrane in your mouth and whether there is already redness and swelling before the pain appears. Observe the size and color of the endostomatitis lesion, whether it bleeds, and whether there is any change in taste, which can be controlled by applying ointment to the lesion. Eat softer foods and foods with high water content, chop ingredients for chewing when cooking, keep food as light as possible to avoid stimulation, and eat more vegetables and fruits rich in vitamin B2. Avoid fatigue and take rest.