Lung cancer patients who cannot breathe are usually more serious. Lung cancer usually manifests as dyspnea, cough, chest pain, chest tightness, and these symptoms will be aggravated in the late stage. Before dying, lung cancer patients usually manifest as sitting up and breathing, unable to lie down, and the dyspnea is more serious, and the patients manifest that they can not catch their breath. However, we cannot understand the condition based on symptoms alone, we need to do relevant examinations for patients, including laboratory examination, imaging examination, bronchoscopy and histopathological examination. Lung cancer patients with breathlessness should consult the doctor in time, contact with the attending doctor to reflect the situation, patients should not take medicine blindly, but follow the standardized treatment under the guidance of doctor’s interview.