Extensive small cell lung cancer generally has a five-year survival rate of no more than 2%, if confined small cell lung cancer five-year survival rate is generally 7% to 20%. Small cell lung cancer is a kind of lung cancer with relatively high malignant degree, and the disease progresses relatively fast, often in the early stage of the disease, it is easy to occur distant metastasis, and because there are no obvious symptoms in the early stage, most of them are already in the middle or late stage at the time of diagnosis, the treatment is more difficult, and the patients’ 5-year survival rate is relatively low. The average overall survival period of extensive small cell lung cancer is generally not more than 1 year, and the 5-year survival rate is relatively low, not more than 2%. In the case of limited small cell lung cancer, the prognosis is relatively better and the 5-year survival rate is higher. Once small cell lung cancer patients are diagnosed, they should actively cooperate with doctors to take treatment. As they are more sensitive to chemotherapy and radiotherapy, early treatment can improve the quality of life and prolong the survival period.