Gastric lavage is the most critical part of the treatment of drug poisoning, but some drug poisoning is contraindicated gastric lavage, the most typical is a strong corrosive substance poisoning strictly prohibited gastric lavage. Whether it is vomiting gastric lavage or gastric lavage machine for intubation gastric lavage, are contraindications to gastric lavage, the most typical is the strong corrosive poison, such as concentrated sulfuric acid, concentrated hydrochloric acid, concentrated nitric acid, nitrobenzene and other corrosive acid and corrosive alkali. Other corrosive liquids require discretion to consider whether gastric lavage should be performed, commonly found in ultra-concentrated carbon tetrachloride and acetaminophen, as well as heavy metals, strongly corrosive drugs and poisons, such as ammoniacal chelating agents and mercapto chelating agents, which are poisonous drugs that are relatively contraindicated for gastric lavage.