Mouth ulcers will appear after consuming fried food, which may be due to traumatic ulcers caused by bad dietary habits, or allergies to some fried food leading to mouth ulcers, as follows. 1. Bad dietary habits: eating too hot food, chewing large pieces of dry and hard food or swallowing too quickly and other dietary habits may lead to oral mucosal damage, resulting in traumatic ulcers, mostly in the cheek, palate, tongue and other parts of the food friction more. 2. Food allergy: the occurrence of mouth ulcers may be related to food allergies, such as potatoes, beef, sesame, etc. If fried food contains allergens, mouth ulcers may occur. There may be other reasons for mouth ulcers after consuming fried food, and it is recommended to go to the hospital in time to receive professional treatment as soon as possible.