Lymph node dissection for lung cancer is an important part of surgical treatment for lung cancer, and attention should be paid to the resection of hilar and mediastinal lymph nodes, including hilar lymph nodes, infratrachordal lymph nodes, paratracheal lymph nodes, chiasmic vein, supra- and infra-left aortic arch lymph nodes, paraesophageal lymph nodes, and infrapulmonary ligament lymph nodes. Lymph nodes should be resected in one piece to prevent fragmentation of lymph nodes, which may cause intrathoracic implantation of cancer cells. According to relevant researches, the probability of mediastinal lymph node metastasis of lung cancer is related to the location of tumor, and focal and sequential metastasis is common, but there are still jumping metastasis, so it is generally advocated to clear it completely.