This trial is a Phase III study. All patients are stage IIIB/C (unsuitable for radical therapy) or IV non-small cell lung cancer(NSCLC), Eastern Cooperative Oncology Group (ECOG) performance status 0-1. The purpose of this study is to evaluate the efficacy and safety of SSGJ-707 comparing Pembrolizumab in subjects with advanced NSCLC whose tumors have a programmed cell death-ligand 1 (PD-L1) Tumor Proportion Score (TPS) greater than or equal to 1%.