Objective To investigate the application and diagnostic value of dual source CT in the clinical diagnosis of lymphocytic interstitial pneumonia. Methods The clinical data of 80 cases of lymphocytic interstitial pneumonia treated in our hospital from June 2014 to June 2016 were analyzed retrospectively and summarized. According to the different diagnostic methods, patients were divided into dual source CT diagnostic group and pathological diagnosis group, and the difference of clinical diagnosis rate between the two groups was compared. Results The main symptoms of the double source CT group were cough and expectoration (23 cases), fever(5 cases), chest tightness(5 cases), pulmonary rales and lung breath sounds reduced(24 cases), chest pain(19 cases), asymptomatic patients(3 cases), and symptoms of pathological group had no significant difference, P>0.05. The diagnosis rate of the pathological group was 95%, significantly higher than that of the dual source CT group (75%) (P<0.05), the difference between the two groups was statistically significant. Conclusion Misdiagnosis of Lymphocytic Interstitial Pneumonia by dualsource CT can be combined with pathological examination to improve the clinical diagnosis rate and reduce misdiagnosis and missed diagnosis.