The limited stage of small cell lung cancer belongs to stage 1 and stage 2. The limited stage of small cell lung cancer is defined as the tumor is confined to one side of the thorax, the same side of the hilar, bilateral mediastinum and the same side of the supraclavicular region, and except malignant pericardial effusion or malignant pleural effusion, it belongs to stage 1 and stage 2, which are also known as early stage and intermediate stage. Small cell lung cancer refers to a group of lung malignant tumors originated from bronchial mucosa or glands. The International Association for the Study of Lung Cancer classifies small cell lung cancer into limited stage and extensive stage, which is of great significance in guiding the treatment plan. The main treatment for small cell lung cancer is radiotherapy combined with chemotherapy. After treatment, 70% of patients with limited stage small cell lung cancer usually have complete remission of symptoms. Since small cell lung cancer is characterized by early and extensive metastasis, it is recommended that patients diagnosed with limited stage small cell lung cancer should be treated under the guidance of doctors as soon as possible to avoid metastasis.