Mediastinal lymph node metastasis after lung adenocarcinoma treatment can be surgically resected if the metastasis is single and small in size; while radiotherapy and chemotherapy are mainly used if the metastasis is multiple, large in size or accompanied with esophageal invasion. Mediastinal lymph node metastasis after lung adenocarcinoma treatment needs to be treated according to the site, size and number of metastasis. Generally speaking, if the mediastinal lymph node metastasis is solitary and the tumor is small in size, it is recommended to perform surgical resection in time as long as the patient meets surgical indications, and then radiotherapy and chemotherapy will be taken according to the situation after surgery. If there are multiple metastases and the tumor is large and invades the surrounding esophagus, then surgery is not recommended, and treatment through radiotherapy, chemotherapy and targeted therapy is recommended.