Objective To investigate the effect of prognostic nutritional index PNI neutrophil - lymphocyte ratio NLR and lymphocyte-monocyte ratio LMR on the efficacy of PD-1/ PD-L1 inhibitors in the treatment of non-small cell lung cancer NSCLC . Evaluation and analysis of prognostic factors. Method According to the inclusion and exclusion criteria the clinical data of 78 patients with NSCLC who were admitted to The Sixth Affiliated Hospital of South China University of Technology / Tumor District 1 from January 2018 to May 2022 were selected for retrospective study. All patients were treated with PD-1/ PD-L1 inhibitor and baseline data were collected and followed up. The differences of NLR LMR and PNI in NSCLC patients with different curative effects were analyzed and NLR LMR and PNI were divided into high and low groups by the median and the differences in curative effect grades of NSCLC patients with different preoperative NLR LMR and PNI were analyzed. According to the follow-up waterlogging the patients were divided into survival group and death group and the univariate differences between the two groups were compared. The prognostic factors were analyzed by binary Logistic regression and the ROC curve was used to analyze the prognostic value of NLR LMR and PNI in NSCLC patients. Result There were significant differences in preoperative NLR LMR and PNI in NSCLC patients with different curative effects P<0. 05 The comparison of NLR values in CR group PR group >SD group >PD group P<0. 05 . The effective rate and disease control rate of PD-1/ PD-L1 inhibitor in low NLR group high LMR group and high PNI group were higher than those in NLR group low LMR group and low PNI group P< 0. 05 . Binary Logistic regression analysis showed that high NLR low LMR and low PNI were prognostic risk factors and treatment intervention time less than third-line and ECOG score 0-1 were prognostic protective factors P<0. 05 . ROC curve analysis showed that the AUCs of NLR LMR and PNI for predicting the prognosis of NSCLC patients were 0. 880 0. 823 and 0. 907 respectively all with good accuracy. The three combined data predicted 0. 934 respectively with higher accuracy. The Z values between NLR LMR PNI and the three combined AUC were 0. 811 2. 061 and 1. 1248 respectively. Conclusion PNI NLR and LMR have good value in evaluating the efficacy of PD-1/ PD-L1 inhibitors in the treatment of NSCLC. High NLR low LMR and low PNI are prognostic risk factors. The treatment intervention time is less than the third-line and the ECOG score is 0-1. Prognostic protective factors and NLR LMR and PNI can be used as prognostic indicators for patients with NSCLC And the combined prediction effect is better.