Lung cancer, of which non-small cell lung cancer (NSCLC) is the most common, has the highest mortality rate worldwide. Tumor immunotherapy, represented by CAR-T cell therapy and immune checkpoint blocking has become a frontier hot spot in the field of cancer research. However, due to the tumor immunosuppressive microenvironment, the lack of tumor specific antigen and drug resistance, the therapeutic effect is still not ideal, and it’s urgent to explore new molecular targets and related molecular mechanisms. Single-cell sequencing is a new technology for high-throughput sequencing of transcriptome at the single-cell level, which can study gene expression in a single cell to understand the function and state of the cell. Using this technology, it is expected to find new targets for cancer treatment and further understand the mechanism of tumor occurrence and development. This article reviews the application and research progress of single cell sequencing technology in non-small cell lung cancer .