Lung is the most common site of extrahepatic metastasis of colorectal cancer, the incidence rate is 10%~25%, and if left untreated, its median survival time is not more than 10 months, and only 5% of patients can survive for more than 5 years.In 1944, Blalock reported the first case of lung metastasis of colorectal cancer with successful surgical resection, which created a precedent for the surgical treatment of lung metastasis of colorectal cancer, and since then, many units also reported the successful experience of surgical treatment of lung metastasis of colorectal cancer successively. Since then, many units have successively reported the successful experience of surgical treatment of colorectal cancer lung metastasis. At present, surgical resection is considered the only effective treatment for isolated lung metastases, and with the accumulation of experience in surgical treatment, more surgical experts believe that as long as the lung metastases can be completely resected, even if the metastases are multiple, surgical treatment is recommended. According to the literature, the 5-year survival rate of surgical treatment can reach 22.0%~48.0%. However, lung metastasis of colorectal cancer is often accompanied by metastasis in other parts of the body, and only 1%~2% of the patients have resectable lung metastases. In 1965, Thomford et al. limited the indications for resection of lung metastases: ①Patients must be able to tolerate surgical treatment; ②Primary cancer has been controlled; ③No metastatic foci in other parts of the body; ④Lung metastatic foci are confined to lungs in the X-ray examination. In 2009, NCCN put forward the following criteria for the indication of surgery for colorectal cancer lung metastases: (1) the lesion can be completely resected according to the anatomical and invasive extent of the lesion and sufficient lung function can be preserved; (2) the primary cancer has been radically resected; (3) resectable extrapulmonary metastatic lesions are not absolute contraindications for resection of lung metastases; (4) some patients with recurrence of lung metastasis can still be considered for surgical treatment.