For different cases, the treatment options for lung metastases are different, as follows: 1. If the number of lung metastases is within 3-5, clinically known as oligometastases, surgical resection is mostly considered. Because most of the lung metastases are located near the peripheral part of the lung, so local wedge resection can achieve the surgical purpose. If the metastases are located deep in the lung, lung segment or even lobectomy is considered. After surgery, the most fundamental thing is to treat the primary tumor, for example, continue to further chemotherapy or targeted therapy for colon cancer lung metastases after surgery; 2. If the number of metastases is >5, or there are organ metastases other than lung, most of them belong to clinical stage IV tumor, and surgical resection of lung metastases is not considered. At this time, further diagnosis and treatment can be carried out according to the primary tumor plan, such as chemotherapy, radiotherapy, targeted therapy or immunotherapy, etc.