Gastric cancer is closely related to the reprogramming of the tumor microenvironment, but the complexity and heterogeneity of the tumor microenvironment presents a significant challenge to the development of individualized and precise diagnostic and treatment strategies for gastric cancer. Studying the reprogramming process of tumor microenvironment, single-cell sequencing technology can depict the “landscape” of the gastric cancer tumor microenvironment at the single-cell level, explore the interactions between cell subtypes and their components, reveal the novel immune mechanisms by which the tumor microenvironment regulates the progression and metastasis of gastric cancer, explore the molecular mechanism of chemo-resistance in the tumor microenvironment of gastric cancer, identify the potential immunotherapy targets for gastric cancer within the tumor microenvironment，and provide a new prediction method for the prognosis of gastric cancer. This will provide more comprehensive and precise evidence for the study of origin, pathogenesis, progression, and immune tolerance in gastric cancer. The following paper reviews the application of single-cell RNA sequencing technology in the reprogramming of the tumor microenvironment in gastric cancer, and attempts to provide new ideas for the precise diagnosis and treatment of gastric cancer.