Objective To analyze the CT imaging features of peripheral lung cancer and focal organizing pneumonia and their differential diagnostic value. Methods A total of 80 patients with peripheral lung cancer and 60 patients with focal organizing pneumonia confirmed by surgery and pathology were selected and they were included into the lung cancer group (n=80) and pneumonia group (n=60) respectively. CT examination was performed before operation, and the imaging data of two groups were statistically analyzed. CT imaging features were compared between the two groups. Results The proportions of cases with lesions in the left or right upper lobe, clear margins, deep lobulated and long and thin spicule sign, mediastinal lymph node enlargement and displayed tumors in the lung cancer group were significantly higher than those in the pneumonia group (P<0.05), while the proportions of cases with lesions in left or right upper lobe of lung, left or right lower lobe, short spicule sign, blurred margins, close to the pleura, liquefaction, necrosis and local pleural thickening were significantly lower than those in the pneumonia group (P <0.05). Namely, there were statistically significant differences between the two groups in the imaging site, shape, density, lobulation, spicule, whether close to the pleura, bronchial congestion sign, local pleural thickening, mediastinal lymph node enlargement and display of tumors (P<0.05). The value added of enhanced CT in lung cancer group was significantly lower than that in pneumonia group (P<0.05), but there was no significant difference between the two groups in other signs (P>0.05). Conclusion CT signs and enhancement of peripheral lung cancer and focal organizing pneumonia are different and characteristic, and differential diagnosis can be performed from perspectives of the location, shape, density, lobulation, spicule, air bronchogram, local pleural thickening, mediastinal lymph node enlargement and display of tumors.