Studies have shown that tau genes in glutathione transferase genes in arabidopsis, wheat, garlic and other plants are related to plant resistance to stress. Based on the analysis of early transcriptomic sequencing data, this study preliminarily studied the candidate gene GbGSTU7, which is suggested to be involved in the anti-wilt regulation of Haidao cotton. GbGSTU7 gene was cloned from Island cotton 06-146 by RT-PCR, and its sequence was analyzed by bioinformatics after sequencing, and the expression characteristics of the gene were studied under the infection of different tissues. The results showed that GbGSTU7 gene CDS was 711bp in length, encoded 236 amino acids, and belonged to the Tau class of GST family. The secondary structure was composed of 5 -folds and 9 -helices, and the tertiary structure was spherical. After fusarium wilt infection, the expression of this gene decreased in the roots of the fusarium wilt resistant variety 06-146, reached the lowest in 48 hours, increased first and then decreased in the stems and leaves, reached the highest in 12 hours in the stems, and reached the highest in 24 hours in the leaves. In the root of the fusarium wilt strain ‘Xinhai 14’, the trend decreased first and then increased, and reached the lowest at 8 hours, and there was no obvious rule in the stem and leaves, but reached the highest at 8 hours in the stem and the highest at 4 hours in the leaves. And in both materials, when the expression of the gene in the root was lowest, the expression in the stem rose to the highest. The results showed that the response of this gene to pathogenic bacteria was different in different materials, and that this gene could respond to the spread of pathogenic bacteria in different tissues when the plant was infected by blight The results of this study lay a theoretical foundation for further research on the blight resistant function of Island cotton GSTU7 gene.