Pulmonary vascular cluster sign is a neovascularized lesion appearing in the lung with occupying lesion, which is commonly seen in alveolar cell carcinoma or adenocarcinoma, but this feature is not necessarily lung cancer. Pulmonary vascular cluster sign is a sign formed around a mass or nodule by CT examination, mainly because the blood vessels and small bronchial tubes around the nodule connect or gather to the lesion, which is one of the characteristic manifestations of lung cancer. However, it can also be seen in benign lesions of the lungs, such as tuberculosis and opportunistic pneumonia. It is not possible to diagnose the specific disease only by the pulmonary vascular cluster sign, and it is also necessary to combine the patient’s chest CT to observe whether there are other signs of lung cancer such as lobular sign, vacuolar sign, burr sign, etc., and to confirm the diagnosis of lung cancer by combining with the clinical manifestations and pathological biopsy.