Indications for gastric tube include difficulty in swallowing and chewing, impaired consciousness or coma, and contraindications include nasopharyngeal carcinoma or acute inflammation. Indications for gastric tube include difficulty in swallowing and chewing, impaired consciousness or coma, upper gastrointestinal tract perforation, gastrointestinal obstruction, acute gastric dilatation, before larger abdominal surgery, preterm infants, and people in critical condition. Contraindications are cancer or acute inflammation in nasopharynx, esophageal varices, upper gastrointestinal bleeding, heart failure, severe hypertension, swallowing corrosive drugs. Gastric tube insertion should be evaluated and operated by professional medical personnel. Complications such as nausea, vomiting, abdominal distension, diarrhea, sugar and electrolyte metabolism disorders, etc., may occur after placing the nasogastric tube, so it is necessary to pay attention to observing the symptoms and monitoring the related indexes, and pay attention to the prevention of slipping off and blockage.