With the accelerated urbanization in China and the difficulty to effectively control air pollution in the near future, the incidence of lung cancer in China is expected to remain on the rise in recent years. According to statistics, the disease spectrum of lung cancer patients has changed greatly from 20 years ago, with adenocarcinoma becoming the most common type. With the popularity of CT screening, more and more small lung nodules are being detected, which may represent benign nodules, early non-invasive adenocarcinoma or microinvasive adenocarcinoma, or invasive adenocarcinoma. Early adenocarcinoma (non-invasive or microinvasive adenocarcinoma) generally appears as a hairy glass-like nodule at CT and is essentially curable with a 5-year disease-free survival of 100% or nearly 100%, respectively, with surgical treatment. The current surgical treatment modalities for these lesions are lobectomy, wedge resection, and segmental lung resection. A growing body of research data suggests that wedge resection and segmental lung resection have similar clinical outcomes to lobectomy. Lobectomy involves removing the entire lobe of the lung where the lesion is located, and hairy glass nodules are usually 1-2 cm in diameter, so for peripheral nodules, lobectomy obviously results in excessive lung tissue loss and has a greater impact on the patient’s lung function. Wedge resection, which generally removes the lung tissue where the lesion is located more than 2 cm from the edge of the lesion, generally has the following disadvantages due to the thin lung edge and thick middle: 1. It is generally limited to nodules immediately adjacent to the dirty pleura; 2. For deeper lesions wedge resection, the thicker lung tissue in the middle will cause the cutter not to effectively form a nail, and patients may have postoperative complications such as air leakage and sputum blood; 3. For larger lesions, it is difficult to ensure negative cut margins. The lung segment is anatomically a complete and independent unit, which is the general term for all the lung tissue in the distribution area of the bronchi and their branches in each lung segment, and is the anatomical unit of lung surgery. The bronchopulmonary segment is conical in shape, with the tip toward the hilum and the base toward the surface of the lung. Each lung segment is accompanied by associated bronchi and arterioles in addition to lung tissue. The division of lung segments is based on the distribution and direction of bronchi. Therefore, as an independent anatomical unit, resection of the lung segment where the tumor is located can ensure complete resection of the tumor while maximally preserving the work of other lung units to achieve the purpose of anatomical resection and radical cure of the tumor. Lung segment resection is also the most recommended surgical treatment for lung cancer in the 2014 American Lung Cancer Diagnosis and Treatment Guidelines. Since the veins, arteries and bronchi of the lung segments are all within the lung, it is difficult to dissect them, and the lung segments are divided by a thin fiber envelope, so it is not easy to distinguish the edges of each lung segment with the naked eye. For these reasons, not many hospitals or centers in China perform lung segment resection.