Lung adenocarcinoma with muscle pain in both legs in advanced stage is mostly considered to be caused by cancer metastasis and venous thrombosis, which need to be treated with pain relieving, anticancer and anticoagulation. 1. Cancer metastasis, after advanced lung adenocarcinoma has metastasized to legs, it may cause muscle pain in both legs, and timely examination is needed to determine the metastasis. If the metastasis meets the indication of surgery, it needs to be resected by surgery in time, and radiotherapy and chemotherapy are needed after surgery; if the pain is obvious, it needs to be treated with pain-relieving drugs such as tramadol and ibuprofen. 2. Venous thrombosis, many lung adenocarcinoma patients are in high coagulation state, so they are prone to lower limb venous thrombosis, intermuscular venous thrombosis, etc. This kind of patients need to use low molecular heparin calcium or low molecular heparin sodium to carry out anticoagulation treatment.