OBJECTIVE From the perspective o f China ’s h ealth service system ，to ev aluate the cost-effectiveness of sintilimab combined with chemotherapy in the first-line treatment of advanced or recurrent non-small cell lung cancer （NSCLC），so as to provide reference for the selection of clinical medication plan and medical and health decision-making. METHODS Based on the ORIENT-11 study data ，a partitioned survival model was established ，and the model period was 21 days to simulate the death of 99％ of the patients. Using quality-adjusted life years （QALY）as an output indicator ，the cost-effectiveness of sintilimab combined with chemotherapy （trial group ）versus chemotherapy alone （control group ）in the first-line treatment of advanced or recurrent NSCLC was evaluated. Cost and utility were discounted using 5％ discount rate ；sensitivity analysis and scenario analysis were used to verify the robustness of the underlying analysis results. RESULTS Under the premise that 3 times of the per capita gross domestic product （GDP）of China in 2020 was used as the threshold of willingness-to-pay （WTP），the patients in the trial group obtained more utility （0.482 QALY）and also spent nearly twice as much as the control group. The incremental cost-effectiveness ratio（ICER）was 334 974.41 yuan/QALY. Univariate sensitivity analysis showed that progression-free survival status utility value ， pemetrexed price ，utility discount rate ，cost discount rate and sintilimab price had a greater impact on ICER. The results of probability sensitivity analysis showed that when the WTP threshold was 3 times of China ’s per capita GDP in 2020，the probability of the trial group ’s plan being cost-effective was 6.5％. The results of the scenario analysis verified the robustness of the underlying analysis results. CONCLUSIONS On the premise of taking 3 times of China ’s per capita GDP in 2020 as the WTP threshold ， sintilimab combined with chemotherapy is not cost-effective for first-line treatment of advanced or recurrent NSCLC compared with chemotherapy alone.