Abstract: At present, there are many studies on the effects of trunk girdling on the morphology and physiology of grape fruits, and few studies on the metabolic mechanism of grape fruit development after trunk girdling. Therefore, in this experiment, physiological parameters and GC-MS was used to conduct metabolic analysis of summer black grapes treated with trunk girdling, and it was found that the contents of TSS and SSC in fruits after trunk girdling were significantly increased, while the contents of TA were significantly decreased. Differential metabolites were significantly enriched in the pathways of galactose metabolism, starch and sucrose metabolism, ABC transporter, glyoxylic acid and dicarboxylic acid metabolism. Sucrose and tartaric acid were the key metabolites involved in the above pathways, and their contents increased and decreased, respectively. By promoting the increase of sucrose content and the decrease of tartaric acid content, the fruit soluble sugar content and the titrable acid content were increased, and the fruit ripening and quality improvement were promoted.