Perioperative Immunotherpay Versus Adjuvant Immunotherapy for Resectable Non-small Cell Lung Cancer

Inclusion Criteria: 1. The patient shall sign the Informed Consent Form. 2. Aged 18 ≥ years. 3. Histological or cytological diagnosis of NSCLC by needle biopsy, and stage II-IIIB (N2) confirmed by imageological examinations (CT, PET-CT or EBUS). 4. Eastern Cooperative Oncology Group (ECOG) performance-status score of 0 or 1. 5. Life expectancy is at least 12 weeks. 6. At least 1 measurable lesion according to RECIST 1.1. 7. Patients with good function of other main organs (liver, kidney, blood system, etc.) 8. Patients with lung function can tolerate surgery; 9. Without systematic metastasis (including M1a, M1b and M1c); 10. Fertile female patients must voluntarily use effective contraceptives not less than 120 days after chemotherapy or the last dose of immunotherapy (whichever is later) during the study period, and urine or serum pregnancy test results within 7 days prior to enrollment are negative. 11. Unsterilized male patients must voluntarily use effective contraception during the study period not less than 120 days after chemotherapy or the last dose of immunotherapy (whichever is later). Exclusion Criteria: 1. Participants who have received any systemic anti-cancer treatment for thymic epithelial tumor, including surgical treatment, local radiotherapy, cytotoxic drug treatment, targeted drug treatment and experimental treatment; 2. Participants with any unstable systemic disease (including active infection, uncontrolled hypertension), unstable angina pectoris, angina pectoris starting in the last three months, congestive heart failure (\>= NYHA) Grade II), myocardial infarction (6 months before admission), severe arrhythmia requiring drug treatment, liver, kidney or metabolic diseases; 3. With activate or suspectable autoimmune disease, or autoimmune paracancer syndrome requiring systemic treatment; 4. Participants who are allergic to the test drug or any auxiliary materials; 5. Participants with Interstitial lung disease currently; 6. Participants with active hepatitis B, hepatitis C or HIV; 7. Pregnant or lactating women; 8. Participants suffering from nervous system diseases or mental diseases that cannot cooperate; 9. Participated in another therapeutic clinical study; 10. Other factors that researchers think it is not suitable for enrollment.