1. Brief medical history: Female, 67 years old, was admitted to the hospital with a right lung nodule found on physical examination. Chest CT suggested that there was a nodule with mixed density in the apical anterior segment of the upper lobe of the right lung, with a maximum diameter of about 2.1 cm. There was a previous history of chronic cough. Preoperative diagnosis: right upper lung heterogeneous shadow, consider malignant possibility, proposed surgery: VATS right upper lung lobectomy. 2. Surgical profile: lumpectomy: no obvious adhesions in the pleural cavity, no pleural metastases, no pleural fluid, undeveloped horizontal fissure and poorly developed oblique fissure. The proposed surgical sequence was: upper pulmonary vein – anterior trunk artery – right upper lobe bronchus – posterior segment artery – horizontal fissure – posterior oblique fissure. The free resection of the superior pulmonary vein and the anterior trunk artery was relatively smooth, but there were several enlarged lymph nodes between the right upper lung bronchus and the right pulmonary artery trunk with heavy adhesions, and the connective tissue between them was tough, which made the free dissection operation extremely difficult. The gap was separated with “Mee’s clamp”. Because of the small gap and the single-port thoracoscopic operation, several attempts to clamp the upper lobe bronchus with the cutting closure device were unsuccessful, and the posterior segment artery was damaged during the repeated operations. Initially, the amount of bleeding was not large, and a lumpectomy was tried to repair the breakage, but the operating space was limited and the surgical view was poor, thus causing further enlargement of the arterial rupture and rapid bleeding. The bleeding site was urgently compressed with a “sponge clamp”, and the left hand was rapidly turned to open the chest, pinching the bleeding site, and the right pulmonary artery trunk was appropriately freed upward and downward. The green nail was cut to close the upper lobe bronchus, and groups 4, 5, 6, 7, 8, and 9 mediastinal lymph nodes were removed to end the operation. Intraoperative bleeding was about 1600 ml, and blood transfusion was about 800 ml. 3.Experience: After the operation, we will review the procedure again and think about what decisions were poorly made and what decisions were reasonable, so as to facilitate the improvement of skills. ①The patient’s lung fissure was poorly developed, and the choice of counterclockwise treatment starting from the upper pulmonary vein was consistent with the principles of lumpectomy. ②After several attempts of lumpectomy to stop the hemorrhage were ineffective, it was a wise decision to timely transit the open chest to stop the hemorrhage. ③After opening the chest, the operator controlled the bleeding calmly with his left hand and appropriately freed the right pulmonary artery trunk centering on the bleeding site, and the timely, concise and effective control of the bleeding was the biggest highlight of this operation and a superiority of the operator, which is worth learning. ④Whether open or lumpectomy, the exposure of the surgical field is crucial, especially so for lumpectomy. During this procedure, if the operating hole is increased to 3 or 4 holes in surgery, it may reduce the difficulty of exposure, thus giving a larger operating space for free work. ⑤ There are two main causes of posterior segment artery injury: first, the gap between the upper lobe bronchus and the right pulmonary artery trunk is not sufficiently freed; second, the posterior mediastinal pleura is not completely opened. ⑥If the timing of the intermediate opening was a little more precise, perhaps intraoperative blood transfusion would not have been needed and the operation time might have been shortened a bit; after all, blood transfusion and prolonged operation time can also cause greater damage to the patient.