Among all lung cancer cases, non-small cell lung cancer accounts for about 80%, and most of the patients are already in the locally advanced stage when they seek medical treatment, so it is difficult to completely remove them by surgery, and radiotherapy is the main means of treatment. In addition to the fact that local tumor cannot be effectively controlled, the main reason for its failure is the emergence of distant metastasis, the incidence of which is as high as 50-60%. Therefore, the combination of radiotherapy and chemotherapy has become the best treatment mode for inoperable locally advanced non-small cell lung cancer, which reduces the recurrence rate and distant metastasis rate and significantly improves the survival rate, especially in recent years, with the continuous application of new precise radiotherapy technology in clinical practice and the emergence of effective chemotherapy drugs, the combination of radiotherapy and chemotherapy has gradually become the common treatment for locally advanced non-small cell lung cancer. The combination of radiotherapy and chemotherapy has gradually become a common treatment for locally advanced non-small cell lung cancer. In terms of the combination of radiotherapy and chemotherapy, there are two types of treatment: sequential radiotherapy and synchronous radiotherapy. When comparing the two treatment modalities, sequential combination therapy is more classic and mature, while simultaneous radiotherapy combination therapy has shown to be superior to sequential therapy in terms of therapeutic efficacy, but at the same time brings about an increase in treatment complications. In March 2005, at the 2nd China Lung Cancer Summit Consensus Meeting held by the Lung Cancer Committee of the Chinese Anti-Cancer Association, the evidence for combined radiotherapy for locally advanced non-small cell lung cancer was discussed, and a consensus on combined radiotherapy for locally advanced non-small cell lung cancer was formed, taking into account the clinical practice in China: Consensus 2: Sequential radiotherapy is recommended as the standard treatment for locally advanced non-small cell lung cancer in clinical practice Consensus 4 recommends concurrent radiotherapy studies for non-small cell lung cancer in hospitals that are in a position to conduct clinical trials. The advantages of combined radiotherapy and chemotherapy: 1. Combined treatment can achieve higher tumor cell killing rate than simple irradiation with the same irradiation dose; 2. inhibit tumor cell repair; 3. cause more tumor cells to die due to DNA double-strand damage; 4. chemotherapy drugs increase the killing effect of radiation on tumor cells; 5. the mass death of tumor cells reduces tumor volume and improves blood supply, The improvement of blood supply, in turn, increases the delivery of anticancer drugs and increases the concentration of local chemotherapy drugs, which increases the killing of tumor cells by chemotherapy drugs. However, it should be emphasized that combined radiotherapy and chemotherapy significantly increase the toxic reactions of normal tissues.