Objective To explore the application of 640-slice spiral CT with volume scan in the diagnosis and differential diagnosis of pulmonary nodules. Methods 28 cases of pulmonary nodules were confirmed by clinical examination, including 8 cases of lung cancer, 12 cases of tuberculoma and 8 cases of inflammatory nodules. The patient was scanned with a Toshiba 640-slice spiral CT scanner, and the results were uploaded to a workstation for processing and diagnosis and discrimination based on the image results. Results There was no significant difference in CT value between all the patients before injection of contrast agent, and there was a significant difference between the three groups after injection of contrast agent and the trend of time difference. Three types of patients with enhanced type there are significant differences in lung cancer patients are mainly enhanced, tuberculosis ball is not strong and inflammatory nodules to strengthen the main way around the strengthening. Conclusion There is a certain value in the diagnosis and differential diagnosis of pulmonary nodules by spiral CT volume scan. It has a certain guiding effect on the diagnosis of solitary pulmonary nodules.