Typical pulmonary interstitial fibrosis is characterized by diffuse reticular or reticular and small nodular shadows in both lungs, starting in the two lower lungs, especially in the subpleural area of the posterior and lateral parts of the two lower lungs, and then expanding to the two upper and middle lung fields and the inner middle band, with a gradual expansion. Fibrous tissue is commonly seen to pull on the small bronchi, causing dilatation of small bronchi, emphysema, and in the advanced stage, diffuse distribution of multiple cystic translucent shadows in both lungs, showing the manifestation of honeycomb lung. Patients with interstitial lung fibrosis have impaired respiratory function and may experience chest tightness, shortness of breath, dyspnea, etc. If there are any of these symptoms, CT examination can be performed to clarify whether there are interstitial lung lesions so as to provide timely treatment.