Objective To analyze the characteristics and changing trends of lung cancer-related projects funded by National Natural Science Foundation of China (NSFC) during 2019–2023, providing a reference for researchers in topic selection and for optimizing scientific research management and resource allocation. Methods Relevant databases, including the NSFC Big Data Knowledge Management Service Platform, were systematically searched to collect information on lung cancer-related funded projects from 2019 to 2023. Quantitative methods were applied to evaluate project categories, funding amounts, and the distribution of host institutions. Project themes were classified according to their titles, keywords, and abstracts, and were subsequently compared with those of projects funded during 2014–2018. Results A total of 1 327 lung cancer-related projects were funded from 2019 to 2023, with total funding of 554.92 million yuan. The Young Scientists Fund and the General Program accounted for 90.3% (1 199/1 327) of the projects and 84.1% (46 675/55 492) of the total funding; the top 10 host institutions comprised approximately 32.0% of all funded projects. Thematic analysis revealed that the core funding directions in the lung cancer field during 2019–2023 focused on molecular mechanisms and signaling pathways. Major research themes included metastasis and recurrence, tumor microenvironment and immunity, and targeted therapy resistance and drug development. Compared with 2014–2018, the proportion of projects focused on tumor microenvironment and immunity, as well as artificial intelligence and medical engineering, increased substantially. Overall, the themes of funded lung cancer projects were dominated by mechanistic studies and demonstrated cross-cutting features intersecting with disease progression, therapeutic resistance, immune regulation, and clinical translation. Conclusion The number of NSFC-funded lung cancer-related projects has continued to grow. Research themes have evolved from pure mechanistic exploration toward immune regulation and translational research, exhibiting characteristics of interdisciplinary integration with emerging technologies and multi-theme cross-fertilization. Researchers are encouraged to align with policy orientations and to emphasize the innovation and translational value of their proposed topics.