Pleural effusion of lung cancer can be controlled by the following methods: a. Performing puncture and drainage of pleural effusion, and then instilling chemotherapy drugs or immunomodulators, such as interferon, into the chest cavity after adequate drainage of pleural effusion. The chemotherapeutic drugs can be cisplatin, bleomycin. It can also be combined with anti-tumor angiogenic drugs, such as recombinant human vascular endothelial inhibitor, to instill into the chest cavity, which can well control the increase of pleural effusion. Secondly, it is more important to do systemic treatment for lung cancer, such as radiotherapy, chemotherapy, immunotherapy or targeted therapy. For example, chemotherapy is the main treatment for pleural effusion caused by small cell lung cancer, and targeted drugs can be used for pleural effusion caused by lung adenocarcinoma. Therefore, lung cancer pleural effusion can be controlled by local treatment and systemic treatment.