In the early stage, we obtained a salt-tolerant gene FtGST2(FtPinG0707941400.01) from tartary buckwheat by genome-wide association analysis, In order to understand the gene structure and type of FtGST2, we found that there were 69 members of the GST gene family in Tartary buckwheat, which belonged to the TCHQD in Glutathione S-transferases. Analysis of the 2000 bp promoter sequence upstream of the gene showed that 35 elements contained 2 ABA response elements and 6 Me-JA response elementsand abscisic acid and jasmonic acid were important hormones for plant regulation of salt stress pathway. In order to further verify the function of FtGST2, we cloned the FtGST2 gene from Zhongku-3, and the expression of FtGST2 in different organs of Tartary buckwheat and the differences in the expression of FtGST2 under different concentrations of NaCl treatment were analyzed. The results showed that the expression level of FtGST2 was the highest in roots, and the expression level of FtGST2 under 100 mM NaCl treatment was significantly higher than that under 50 mM NaCl treatment and no treatment. At the same time, we constructed Arabidopsis thaliana and hairy roots overexpressing FtGST2, and detected the seed germination rate, taproot length, hairy root fresh weight and physiological indexes of transgenic materials under salt treatment. The results showed that the germination rate and root length of Arabidopsis thaliana overexpressing FtGST2 were higher than those of the wild-type with the same treatment, and there was no significant difference between the hairy roots overexpressed by FtGST2 and the control group (A4) under the untreated conditions, while the fresh weight of hairy roots under 100 mM NaCl treatment was significantly higher than that of the control A4. The expression levels of overexpressed hairy roots and A4 hairy roots at different times under 100 mM NaCl treatment showed that the expression level of FtGST2 gene was the highest at 3 h after salt stress, decreased at 6 h, and increased at 12 h. In addition, the physiological indexes of hairy roots were detected, and it was found that the overexpression of FtGST2 gene could effectively improve the salt tolerance of tartary buckwheat hairy root overexpression lines. The above experiments preliminarily verified the salt resistance function of FtGST2 gene, which laid a certain foundation for the subsequent breeding of salt-tolerant varieties of tartary buckwheat.