Lung cancer is one of the highly prevalent tumors in China, and its incidence rate is on the rise year by year. There are many causative factors of lung cancer, smoking, environmental pollution, family genetics and chronic lung lesions are all high-risk factors. Lung cancer develops on the bronchial mucosa and alveolar epithelium at all levels in the lung and keeps growing into the official cavity and outside the tube to form masses, producing local compression and obstruction symptoms. Late stage lung cancer can also metastasize to the cranium, liver, kidney, bone, pleural cavity and other parts of the body to form new lesions through blood, lymphatic tract and pleural implantation, causing serious harm to the organs there. The early symptoms of lung cancer are relatively mild and most of them are not easy to attract attention. Generally, they are dry cough with unknown reasons, little sputum, occasionally blood in the sputum and pinching pain in the chest. The symptoms in the middle stage are usually cough, sputum, blood in sputum, chest pain and fever, which are not too severe but hard to control. Late stage symptoms are usually chest tightness, shortness of breath, severe chest pain, hoarseness, headache, vomiting, sudden aggravation of visual impairment, neck mass, pain in joints of limbs and enlargement of finger ends, and some patients have corresponding manifestations of liver and bone metastasis. The prognosis of lung cancer is relatively poor, and the most critical influencing factor is the presence or absence of potential metastases at the time of treatment. Simple lung cancer lesions can generally be removed and controlled by relatively complete surgery, but patients with distant metastases are very difficult to treat and must be treated with regular systemic chemotherapy and local treatment to barely control them, and the long-term results are often poor. Recently, targeted therapy and individualized therapy combined with the traditional three pillars of therapy have greatly improved the clinical efficacy of lung cancer. Unexplained cough, chest pain and blood in sputum are the danger signs of lung cancer, which should be detected in time by X-ray examination in hospital. Regular checkups once or twice a year are the best way to screen lung cancer, which can ensure detection and timely treatment within six months of onset, as well as detect other diseases without delaying valuable treatment due to atypical symptoms. The incidence age of lung cancer has involved young and middle-aged people under the age of 40, causing considerable harm to patients, and early detection and treatment is the only effective way!