Objective：This study aims to explore METTL3 combined with programmed death cell ligand 1（PD-L1）detection in predicting the therapeutic effect and prognosis of NSCLC patients with programmed death cell protein 1（PD-1）inhibitors treatment. Methods：Primary lesion tissues from NSCLC patients were collected. The protein expression of PD-L1 and METTL3 was detected by immunohistochemistry，and the association of METTL3 with the effect of PD-1 inhibitor treatment and prognosis in patients with NSCLC was analyzed. Results：A total of 228 cases were collected. Among them，the protein expression of METTL3 was related to the pathological type，Eastern American Oncology Collaborative Group（ECOG）score，therapeutic plan，therapeutic effect and Response Evaluation Criteria in Solid Tumors（RECIST）factors. Patients with high METTL3 protein expression had a median progression-free-survival（PFS）of 12.33 months，while those with low or no METTL3 protein expression had a median PFS of 6.50 months. In NSCLC patients treated with PD-1 antibody，high METTL3 protein expression was associated with better PFS. The median overall-survival（OS）of patients with high METTL3 proteine xpression was 23.54 months，and OS of patients with low or no METTL3 protein expression was 20.93 months. Patients with high METTL3 protein expression were associated with better OS. Conclusion：METTL3 protein may be a new target for predicting the efficacy of PD-1 inhibitors treatment in patients with NSCLC.