Single-cell RNA-seq （scRNA-seq） can describe the changes of gene expression in a single tumor cell. And it can reveal the status and function of tumor cells, and capture the extensive transcriptome heterogeneity in the cell population. The application of scRNA-seq can monitor the specific highly expressed genes in esophageal squamous cell carcinoma （ESCC）, and it can also monitor genes related to radio chemotherapy resistance in tumor cells, which is helpful to provide more accurate auxiliary diagnosis for ESCC. Besides, scRNA-seq can evaluate the recurrence risk and survival time of patients. An in-depth study of the relationship between tumor cells and tumor microenvironment in ESCC will provide a theoretical basis for developing a new immunotherapy scheme for ESCC.