Objective: Tetragenococcus halophilus is a kind of lactic acid bacteria， the high polymer exopolysaccharide produced by it has important application value. In order to explore the molecular mechanism of exopolysaccharide produced by Tetragenococcus halophilus， the whole genome of the strain was sequenced and analyzed， which provided a theoretical basis for the production and application of exopolysaccharide from Tetracococcus halophilus. Methods: The whole genome of Tetragenococcus halophilus CGMCC 3792 was sequenced by nanopore third-generation sequencing technology， and the gene prediction and functional annotation were performed by bioinformatics method. In addition， the genes related to the biosynthesis of exopolysaccharide were further explored， and the molecular mechanism of exopolysaccharide synthesis by Tetragenococcus halophilus CGMCC 3792 was analyzed deeply at the gene level. Results: The total length of the genome of Tetragenococcus halophilus CGMCC 3792 was 2 573 722 bp， encoding 2 633 genes. The biosynthesis pathway of exopolysaccharide was analyzed， and results showed that exopolysaccharide could be synthesized from mannose， fructose， maltose， glucose and cellobiose. Through genomic analysis， it was found that the genome contained a 15.4 kb exopolysaccharide gene cluster， including the regulating genes epsA and epsB， the chain length determining genes epsC and epsD， and two glycosyltransferase genes as well as the flippase encoding gene wzx. Conclusion: This study revealed the molecular mechanism of exopolysaccharide production by Tetragenococcus halophilus CGMCC 3792 at the gene level， which laid a foundation for its industrial application.