This trial is a randomized, controlled, multicenter, open-label study, planning to enroll 116 subjects with resectable stage II-IIIa squamous NSCLC confirmed by histopathology or cytology, aiming to evaluate the efficacy and safety of serplulimab compared to nivolumab combined with chemotherapy in neoadjuvant therapy. This is a clinical trial from Eastern Cooperative Thoracic Oncology Project (ECTOP), numbered as ECTOP-1036.

Inclusion Criteria:

1. Age ≥ 18 years and ≤ 75 years at time of study entry.
2. The International Federation of Gynecology and Obstetrics (FIGO) 2018 Stages II-IIIA squamous non-small cell lung cancer confirmed by histopathology or cytology.
3. The patient with stage II-IIIA squamous non-small cell lung cancer confirmed by histopathology or cytology;
4. Able to tolerate complete lung cancer resection;
5. WHO/ECOG performance status of 0 or 1.

Exclusion Criteria:

1. Other pathological histological types of non-small cell lung cancer subjects, including adenocarcinoma subjects, squamous-adenocarcinoma mixed cancer subjects, and NSCLC containing components of small cell lung cancer and neuroendocrine carcinoma.
2. EGFR sensitivity mutation or ALK, ROS1 gene rearrangement;
3. Known severe allergy to any components of carboplatin/albumin paclitaxel and other drugs;
4. Central nervous system (CNS) or leptomeningeal metastases confirmed by imaging or pathology