Multiple circumferential lesions under the pleura of the left upper lung can be seen in respiratory diseases such as tuberculosis, silicosis and lung tumor. 1. Tuberculosis: cough, sputum, blood in sputum, low fever in the afternoon, malaise, night sweats, etc. PDD test is positive, and bacillus antacidus can be detected in sputum. 2. Silicosis: Silicosis usually has the experience of working in mines, with a long course of disease, and is common in men. 3. Lung tumor: Lung tumors are common in middle-aged and old men with a history of smoking, and the clinical symptoms may be chest pain, hemoptysis, and blood in sputum. Long-term chronic inflammation in the left upper lung leads to fibrosis in the lung, and CT can show multiple ring-shaped lesions under the pleura of the left upper lung. When CT examination shows multiple ring-shaped lesions under the pleura of the left upper lung, the patient should consult the thoracic surgery department in time, improve the blood routine, blood sedimentation, c-reactive protein and other tests to further diagnose the disease, and carry out treatment under the guidance of the doctor.