Tapioca poisoning is caused by eating unpoisoned or incompletely poisoned potatoes. The cassava contains a sub-allotrope, after its own sub-allotrope enzyme action, can precipitate free hydrocyanic acid and cause poisoning. Cassava contains hydrocyanic acid, which is very harmful to the human body, therefore, the masses publicize the toxicity of cassava, preventing the ingestion of poisonous or incomplete detoxification of cassava, the old, the weak, pregnant women and young children should not use cassava as food. Once poisoned, rescue must be rapid, scrambling for time, even for critically ill patients, on the one hand, give symptomatic supportive treatment, while using antidotes. The key to preventing cassava poisoning is not to eat it raw, but to peel off the inner skin and cook it. Clinical manifestations of tissue hypoxia and central nervous system damage symptoms, severe cases of respiratory and reflux center paralysis and death. Cassava poisoning often occurs in the southern region of China, especially in newly planted areas. According to the clinical manifestations, combined with a history of eating cassava diagnosis is generally not difficult to establish. At present, the first choice of detoxification drugs amyl nitrite, nitrite and sodium thiosulfate three drugs combined application, the role of rapid and significant efficacy. Early diagnosis, rapid treatment is the key to rescue cassava poisoning.