Sulfur dioxide is colorless at room temperature with a strong pungent irritant gas. It is a strong irritant to the eyes and respiratory tract, and inhalation of high concentration of sulfur dioxide can cause laryngeal edema, vocal cord edema, pulmonary edema leading to asphyxiation. Its toxicity is due to the generation of sulfite and sulfuric acid on the surface of wet mucous membranes, which produces strong irritation to the eyes and respiratory tract. Treatment 1. immediate removal from the scene of poisoning, sedation and warmth. 2. release bronchospasm and keep the airway open. 3. ultrasonic nebulization inhalation therapy. 4. pulmonary edema treatment: reasonable oxygen therapy; early, adequate and short course application of adrenal glucocorticoids. 5. pneumonia and secondary infection treatment. 6. tracheotomy: prompt tracheotomy should be performed when asphyxia is caused by laryngeal edema, vocal cord edema, spasm, ARDS, etc. 7. . 7.Strengthen nursing and supportive treatment.