• The patient shall sign the Informed Consent Form.

• Aged 18 ≥ years.

• Histological or cytological diagnosis of NSCLC by needle biopsy, and stage III confirmed by imageological examinations (CT, PET-CT or EBUS).

• Eastern Cooperative Oncology Group (ECOG) performance-status score of 0 or 1.

• Life expectancy is at least 12 weeks.

• At least 1 measurable lesion according to RECIST 1.1.

• With the feasiblility or anticipated feasiblility after neoadjuvant therapy to receive radical surgery;

• Patients with good function of other main organs (liver, kidney, blood system, etc.):

‣ ANC count ≥1.5×10\^9/L, platelet count ≥100×10\^9/L，hemoglobin ≥90 g/L;

⁃ the international standard ratio of prothrombin time (INR) and prothrombin time (PT) \< 1.5 times of upper limit of normal (ULN);

⁃ Partial thromboplastin time (APTT) ≤1.5×ULN;

⁃ Total bilirubin ≤1.5×ULN;

⁃ Alanine aminotransferase (ALT) aspartate aminotransferase (AST) ≤2.5×ULN, or ALT and AST ≤5×ULN in the patients with liver metastatic tumor.

• Patients with normal lung function can tolerate surgery;

⁃ Without systematic metastasis (including M1a, M1b and M1c);

⁃ Fertile female patients must voluntarily use effective contraceptives not less than 120 days after chemotherapy or the last dose of Sintilimab (whichever is later) during the study period, and urine or serum pregnancy test results within 7 days prior to enrollment are negative.

⁃ Unsterilized male patients must voluntarily use effective contraception during the study period not less than 120 days after chemotherapy or the last dose of Sintilimab (whichever is later).