Objective To analyze application value of CT and MRI in diagnosis of benign and malignant solitary pulmonary nodules. Methods The clinical data of 54 patients with solitary pulmonary nodules confirmed by surgery, pathological puncture or follow-up in our hospital. The clinical data were retrospectively analyzed. CT and MRI findings of solitary pulmonary nodules were analyzed, and the clinical value of CT and MRI in diagnosis of benign and malignant solitary pulmonary nodules were summarized. Results CT diagnostic accuracy rate was 92.59%, MRI accuracy was 75.93%. The accuracy of CT was significantly higher than MRI (P<0.05). The peak heigh (PH) and the ratio of artery to pulmonary artery (SPH/PPH) of malignant nodules and inflammatory nodules were significantly higher than those of benign nodules (P<0.05) but there was no significant difference in CT contrast enhanced scan parameters between malignant nodules and inflammatory nodules (P>0.05). Conclusion Diagnostic value of CT in solitary pulmonary nodule is better than MRI. The morphological characteristics of lesions can be clearly displayed. The display rates to internal structure, and calcification signs are good. It is safe, noninvasive and easy to operate