Pulmonary sequestration is a rare congenital lung malformation that more commonly occurs in the left lung, mainly near the lower mediastinum. It is rarely observed in patients with extralobar sequestration in adulthood. We report the case of a 55-year-old man with recurrent fever and cough lasting for about 1 month, who was admitted to our hospital. His past history was unremarkable. The final diagnosis of extralobar sequestration was dependent on three-dimensional computed tomography angiography (3D CTA), which showed an abnormal blood supply vessel to the consolidation from the aortic arch. The patient underwent a left pulmonary sequestration resection, and the pathological examination also verified the diagnosis postoperatively. 3D CTA images can provide an aberrant vessel anatomy map for the surgeon and play a decisive role in the detection of pulmonary sequestration.