Inclusion Criteria:  Patients voluntarily participate in this study, signed informed consent. Patients aged between 18 -75 years; According to the eighth edition of AJCC and the standard of the VALG two-stage staging method, the patient is confirmed by histology or cytology as limited-stage SCLC (stage I-III, any T, any N, M0) and cannot be operated on. Patients with ECOG PS Scoring: 0~1 point Patients with concurrent chemoradiotherapy must comply with relevant regulations. PCI is given according to the judgment of the investigator. Patients with normal organ function, the following criteria are met: (1) blood routine examination criteria (without blood transfusion in 14 days) : a) hemoglobin (HB) ≥90g/L; b) absolute neutrophil count (ANC) ≥1.5×10e9/L; c) platelet (PLT) ≥80×10e9/L; (2) biochemical tests meet the following criteria: a) total bilirubin (TBIL) ≤1.5 times of upper limit of normal (ULN); b) alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤2.5 ULN, if liver metastasis occurred, ALT and AST ≤5 ULN; c) serum creatinine (Cr) ≤1.5 ULN or creatinine clearance (CCr) ≥60mL/min. For women of child-bearing age, the pregnancy test results (serum or urine) within 1 week before enrolment must be negative. They will take appropriate methods for contraception during the study until the 6 months post the last administration of study drug. For men (previous surgical sterilization accepted), will take appropriate methods for contraception during the study until the 6 months post the last administration of study drug.  Exclusion Criteria:  Small cell and non-small cell mixed lung cancer Extensive stage small cell lung cancer Central lung tumors that imaging shows tumor lesions invade local large blood vessels; or with significant pulmonary cavum or necrotizing Less than 4 weeks from the last clinical trial or participating in other clinical studies. History:  1) Brain metastasis or spinal cord compression 2) Other active malignancies that require simultaneous treatment. 3) History of immunodeficiency, including HIV-positive or other acquired, congenital immunodeficiency disease, or history of organ transplantation.  4) History of mental drug abuse and cannot be cured or have mental disorders 6. Patients with any severe and/or uncontrolled disease, including:  blood pressure control is not ideal (systolic blood pressure ≥ 150 mmHg, diastolic blood pressure ≥ 100 mmHg); Significant cardiac disease as defined as: grade I or greater myocardial infarction, unstable arrhythmia (including corrected QT interval (QTc ) period between male or greater 450 ms, female or greater 470 ms); New York Heart Association (NYHA) grade II or greater heart dysfunction , or Echocardiography reveal left ventricular ejection fraction (LVEF) less than 50% Decompensated diabetes or other remedies for high-dose glucocorticoid therapy. Exacerbation of chronic obstructive pulmonary disease (COPD) or other serious respiratory diseases that require hospitalization Active or uncontrollable serious infection (≥CTC AE Level 2 infection); Uncontrolled pleural effusion, pericardial effusion and abdominal effusion requiring repeated drainage. Urine routine test protein≥++, and confirmed 24 hours urine protein>1.0 g; 7. Imaging shows that the tumor has been violated around important vascular or the researchers determine the tumor is likely to invade important blood vessels caused by fatal bleeding during the follow-up.  8. Patients who received a major surgical treatment or severe trauma, the effects of surgery or trauma have been eliminated in less than 2 weeks before being enrolled 9. Patients with clinically significant hemoptysis occurred within 3 months prior to enrollment (greater than 1/2 teaspoon of bright red blood). History of clinically relevant major bleeding event (e.g. gastrointestinal hemorrhage, hemorrhagic acne, bleeding gastric ulcer, occult blood test ≥ ++, or vasculitis, etc.) 10. Patients who have arterial/venous thromboembolism events within 6 months before being enrolled, such as cerebrovascular accident (including transient ischemic attack, cerebral hemorrhage, cerebral infarction), deep vein thrombosis and pulmonary embolism, etc.  11. Coagulation disfunction（INR>1.5 or PT>upper limit of normal(ULN)+4s or activated partial thromboplastin time (APTT) >1.5 upper limit of normal (ULN)）, hemorrhagic tendency or receiving the therapy of thrombolysis or anticoagulation.  12. At the discretion of the investigator, the patient may have other factors that may cause the study to be terminated midway.