Acute interstitial pneumonia is a rare, rapidly developing fulminant lung injury. It is an acute, damaging lesion of the lung. It starts rapidly (within days to weeks) with fever, cough and shortness of breath, followed by respiratory failure, similar to idiopathic ARDS of unknown origin. AIP has a very high mortality rate (>60%), with most deaths occurring within 1 to 2 months. The average survival time is very short, and most patients die within 1-2 months. There is no gender difference in the onset of AIP, and the average age of onset is 49 years. More than half of the patients have sudden onset of fever, dry cough and pus sputum in case of secondary infection; chest tightness, weakness, progressive dyspnea, cyanosis, wheezing, chest tightness or girdling sensation; pestle-like fingers (toes) soon appear, scattered popping sounds can be heard at the base of both lungs, spontaneous pneumothorax can occur in some patients, antibiotic treatment is ineffective, most of them die of acute respiratory failure and right heart failure within 2 weeks to 6 months. If glucocorticosteroids are applied in sufficient quantity early, the condition can be relieved or even cured.