The stem cell differentiation ability of small cell lung cancer is faster than that of other lung cancers, so it is the most malignant among lung cancers. Small cell lung cancer can be classified as limited type or extensive type. Other limited type of small cell lung cancer can be cured by applying local treatment combined with systemic treatment. For example, radiotherapy, surgical treatment, combined chemotherapy, at least more than 1/3 can be cured. However, the treatment intensity of small cell lung cancer is more intense than other non-small cell lung cancers, and the damage to the body is relatively much larger, which needs to further improve the immune function of the body to fight against cancer cells through autoimmunity. Immunonutrients can be consumed to increase the immune function of the body, and nutrition should be strengthened at the same time, especially increasing the intake of protein, which is beneficial to the repair of the body. However, the chances of cure for extensive small-cell lung cancer are very small no matter which kind of treatment is available at present.