CT perfusion imaging, a non-invasive functional imaging method, can accurately reflect the hemodynamic changes of pulmonary nodules. It plays an important role in the diagnosis, differential diagnosis, treatment effect assessment and prognosis prediction. This article reviews the hemodynamics of pulmonary nodules, the characteristics of the blood flow of CT perfusion imaging of the pulmonary nodules, the characteristics of the CT perfusion technique of the pulmonary nodules and the status of the clinical application in the characterization of pulmonary nodules.