Lung cancer patients presenting with leg weakness should be analyzed and judged specifically. If bone metastasis of lung cancer occurs, it suggests that it belongs to grade 4, in which case the overall prognosis of the patient is poor. Generally speaking, the median survival period of untreated distant metastasis is 3-4 months, and the survival rate of 1 year is about 15%, which refers to the occurrence of distant metastasis of lung cancer. If the weakness and leg weakness is caused by the serious consumption of lung cancer itself, it needs to be judged according to the specific stage of the patient, so the specific reason should be analyzed and judged when the leg weakness of lung cancer occurs.