OBJECTIVE To estimate the cost-effectiveness of penpulimab combined with chemotherapy versus chemotherapy alone in first-line treatment of advanced squamous non-small-cell lung cancer （sq-NSCLC）. METHODS From the perspective of Chinese health system， cost-utility analysis was used to evaluate the cost-effectiveness of penpulimab combined with chemotherapy （paclitaxel + carboplatin） versus chemotherapy （paclitaxel + carboplatin） in first-line treatment of sq-NSCLC. A three-health states Markov model was constructed with R packages， and clinical data used in the model were derived from the AK105-302 clinical trial. Costs and utilities were collected from the open-access database and published literature. The quality-adjusted life-years （QALY） was used as the utility index， and the willingness-to-pay （WTP） threshold was set at three times China’s per capita GDP in 2024， equivalent to 287 247 yuan/QALY. The cost-effectiveness of the schemes was evaluated by comparing the incremental cost- utility ratios （ICER） of the two schemes with the WTP threshold. One-way sensitivity analysis and probabilistic sensitivity analysis （PSA） were used to verify the stability of the basic analysis results. RESULTS Compared with chemotherapy， penpulimab combined with chemotherapy increased 0.73 QALY with an incremental cost of 150 681.93 yuan， and the ICER was 206 413.60 yuan/QALY. One-way sensitivity analysis showed that the utility of progression-free survival was the most sensitive factor on ICERs. At the WTP threshold of 3 times China’s per capita GDP， the economic probability of this scheme was 98.80%. At the WTP threshold of 1 times China’s per capita GDP， the probability of ICER being cost-effective was less than 0.01%. CONCLUSIONS For patients with advanced sq-NSCLC， penpulimab combined with chemotherapy is a cost-effective first-line treatment option when WTP threshold is 3 times China’s per capita GDP.