Small cell lung cancer (SCLC) accounts for about 15-20% of all lung cancers. Compared with non-small cell lung cancer, its biological behavior is worse, its disease develops rapidly, and it is prone to early metastasis, and about 60%-70% of patients are already in advanced stages when diagnosed. It is currently thought to be associated with smoking, environmental and genetic factors. There is increasing evidence that autocrine growth rings, proto-oncogenes and oncogenes are associated with small cell lung carcinogenesis. It is now believed that SCLC originates from Kulchistky cells in the bronchial epithelium and mucus glands, and the tumor cells have a more obvious neuroendocrine differentiation tendency and cause some abnormal endocrine syndromes such as abnormal antidiuretic hormone syndrome, Cushing’s syndrome and carcinoid syndrome in clinical practice. If the lesion is confined to one side of the chest without mediastinal lymph node metastasis ((T1-2N0) surgical treatment is superior to thoracic radiotherapy, but postoperative combined adjuvant chemotherapy is required. Phase II clinical studies have shown that preoperative and postoperative chemotherapy are feasible with a 5-year survival rate of 10-50%. Because 10-15% of small cell lung cancers are mixed with non-small cell lung cancer components, limited-stage small cell lung cancers that do not completely remit or recur after conventional chemoradiotherapy may be considered for surgical resection. From the available evidence-based medical evidence, it can be concluded that the combination of radiotherapy and EP regimens is currently the best treatment option for patients with limited-stage small cell lung cancer, and early involvement of radiotherapy is preferable to late involvement (1-2 cycles after the start of chemotherapy), and the toxicity of combination therapy such as esophagitis is tolerable for patients with good PS scores. In addition, prophylactic brain irradiation for patients in complete remission is the current standard of care for limited stage small cell lung cancer. The EP regimen has a response rate of 80-100% and a complete remission rate of 50-70%. The synergistic effect of cisplatin and pedialyte glycosides, as well as moderate hematologic toxicity and mild mucositis are factors that recommend the use of the EP regimen in combination with radiation therapy.