Bilateral lung gap fine change is the result of CT examination, which may be caused by pulled bronchial dilatation, lobular septal thickening and so on. 1. Pulled bronchial dilatation: it belongs to the chronic progressive pathogenesis, may be due to bronchial obstruction caused by bronchopulmonary infections, bronchial dilatation due to destruction of the wall or pulling by peripheral tissues, CT examination results show double lung gap fine changes, and symptoms such as coughing and hemoptysis will appear. 2. Thickening of interlobular septum: it may be caused by the imbalance of autoimmune system, CT examination results show double lung gap fine changes, a pathological feature of double lung interlobular septum thickening, and there may be varying degrees of progressive aggravation of respiratory distress. Therefore, CT examination results show double lung gap fine change patients, should go to the hospital as soon as possible to identify the cause of the disease, after diagnosis and actively cooperate with the doctor for treatment.