In recent years, the incidence and mortality rate of lung cancer in China are increasing year by year, and it has become the most common malignant tumor that seriously endangers human health. Surgical resection of lung cancer, its metastatic lymph nodes and adjacent tissues is the first choice and basic method of lung cancer treatment today. Central lung cancer is already stage IIIb (T4) when it invades the root of the pulmonary vein or the left atrium, but recent studies have found that although these lung cancers are locally advanced, many of them do not have distant metastases, and if radical pneumonectomy and partial resection of the left atrium can be performed, not only can the surgical resection rate be improved, but patients still have a better outcome [1-3]. If combined with postoperative radiotherapy, chemotherapy and bioimmunotherapy, many patients can also achieve long-term survival. The principle of lung cancer treatment is “to remove the tumor as much as possible and to preserve the lung function as much as possible”. In lung cancer surgery, it is not uncommon to find lung cancer invading the left atrium or involving the base of the pulmonary vein and the confluence of the left atrium along the pulmonary vein trunk. In the past, surgery was mostly abandoned for such lesions. Patients in this category generally survive only 3-6 months, and most of them die due to cancerous pericardial effusion, pericardial tamponade, arrhythmia and/or distant metastasis. Pulmonary resection with partial resection of the left atrium is a new and challenging technique used in recent years for the surgical treatment of locally advanced lung cancer in which the tumor has involved the root of the pulmonary vein and the wall of the left atrium]. Of course, the possibility of resection depends on factors such as the extent of tumor invasion and the surgical skill of the surgeon. Although it is controversial, atrial resection can improve the quality of life and prolong the survival of patients. The 5-year survival rate of 75 patients with locally advanced lung cancer treated with partial resection of the lung and left atrium was 31.2%, which greatly improved the quality of life and prolonged the survival period. Whether lung cancer invades the root of pulmonary vein and left atrium is difficult to determine by routine preoperative examination. c t , m r i , and echocardiography are of value. However, when the pericardium is only compressed and close to the heart, imaging examination is also difficult to determine accurately, but must rely on intraoperative exploration to determine. Lung cancer invading the left atrium is already stage IIIb (T4), which is locally advanced lung cancer with high possibility of distant metastasis, and the operation is more traumatic. Therefore, the indications should be carefully selected, especially when the tumor involves multiple organs (such as esophagus, aorta, aorta, aorta, main pulmonary artery, superior vena cava, atrium and more than 2 organs), or extensive mediastinal lymph node metastasis, or when the tumor is not completely resected. It is generally considered that this procedure is suitable for the following patients: ① distant metastases in the cranial, abdominal and skeletal areas are excluded by CT, isotope imaging electron computed tomography (ECT), etc. (M0); ② no supraclavicular, cervical, contralateral mediastinal and hilar lymph node metastases (non-N3); ③ the patient is in a good general condition, can tolerate surgery, and it is estimated that the lesion and involved tissues can be completely removed by surgery; ④ non-small cell lung cancer (5) no cancerous pericardial effusion, and the estimated extent of atrial resection is less than 1/3. The risk of surgery is that if the auricular clamp slips or the suture tears after cutting the left atrial wall, causing hemorrhage, improper treatment may lead to death. Some authors have proposed that the left atrium should be dissected after prepositioning a mattress suture on the distal side of the auricular clamp, which is easy to operate and does not risk the left atrial wall slipping out of the auricular clamp. In recent years, vascular sutures have been used to close the left atrial wall, which is fast and reliable, but more costly. We used two auricular clamps to clamp the left atrium separately and used Prolene suture to close the left atrium cutting edge continuously back and forth. Before resection of the left atrial wall, the heart is sprayed with 1% procaine or lidocaine for surface anesthesia. Generally, the pulmonary vein should be treated first to prevent the tumor embolus from dislodging or metastasis due to surgical operation. When the tumor is large, it is more difficult to expose the pulmonary vein. The following measures should be taken: ① control the amount and speed of fluid immediately after intraoperative dissection of the left atrium; ② monitor the blood pressure and heart rate for 24 hours after surgery; ③ control the amount and speed of fluid infusion; ④ administer cardiac and diuretic therapy according to the condition; ⑤ extend the duration of oxygenation, usually 2-3 days. In our opinion, advanced stage T4 lung cancer with invasion of pulmonary veins in the left atrium or pericardium should be considered for aggressive surgical treatment if there is no N3 metastasis and as long as complete resection can be technically achieved. In addition to complete resection of the primary cancer site and the infiltrating organs, systematic clearance of the mediastinal lymph nodes in the chest should also be performed to obtain radical resection. Postoperative treatment should be routinely supplemented with chemotherapy, radiotherapy and bioimmunotherapy to further improve the survival rate.