Lung cancer patients’ inability to eat can be treated by symptomatic treatment as well as causative treatment according to different reasons, such as being in the advanced stage of cancer, after radiotherapy, tumor metastasis leading to esophageal obstruction, and so on. 1. Symptomatic treatment: For those who cannot eat due to advanced stage of cancer, they can be treated with intravenous nutritional support, such as fat milk injection, 10% dextrose, potassium chloride, vitamin C injection, vitamin B6 injection and so on; If the inability to eat is caused by radiotherapy, it can be treated by taking oral medicines such as megestrol acetate, vitamin B6 tablets, metoclopramide and so on under the guidance of physicians. 2. Causal treatment: if the esophageal obstruction is caused by tumor metastasis, stenting can be used to relieve the obstruction; lung cancer patients can also be treated by oral targeted drugs and surgical resection. It is suggested that patients should go to the hospital and choose reasonable medicines and methods to treat under the guidance of doctors, and do not use medicines blindly.