Abstract：Objective To study the significance of 64-slice spiral CT volume scan in the differential diagnosis of solitary pulmonary nodules. Methods 32 patients with solitary pulmonary nodules diagnosed by pathological examination were selected in our hospital from May 2018 to May 2020, including 9 cases of inflammatory nodules, 13 cases of tuberculosis nodules and 10 cases of lung cancer nodules. CT plain scan and dynamic enhanced scan before operation were underwent, the Edge, internal structure, CT value and enhancement degree of the nodules were observed. The enhancement time was 28, 60 s and 180 s. The results were comprehensively analyzed. Results There were no significant difference in plain CT values between inflammatory nodules, tuberculous balls and small lung cancer（t＝1.335, all P＞0.05）; At 28, 60 s and 180 s after injection of contrast agent, CT values of the three nodules showed significant differences with time（t＝10.238, 22.395, 16.548, all P＜0.05）. The three types of enhanced small and medium lung cancer were more than homogeneous enhancement, tuberculous nodules were more than capsular enhancement or no enhancement,inflammatory nodules were more than peripheral enhancement. Conclusion 64 slice spiral CT volume scan is of great value in different the nature of small pulmonary nodules.