INTRODUCTION: The carbohydrates secreted by plant roots play a crucial role in modulating the carbon source supply and metabolic activity of soil microorganisms. RATIONALE: In order to unveil the response mechanism of root-secreted carbohydrates in salt-tolerant plants to the intensity of salt stress, this study focused on the salt-tolerant forage grass Thinopyrum ponticum. Four levels of salt stress intensity were conducted by adding NaCl, including control, light, moderate, and heavy stress conditions (with soil salt contents of 0%, 0.2%, 0.4%, and 0.6%, respectively). Untargeted metabolomics techniques were employed to analyze the compositional alterations of root-secreted carbohydrates and their correlations with the rhizosphere soil properties were evaluated. RESULTS: The results demonstrated that: (1) Compared to the control, salt stress significantly decreased the contents of five types of carbohydrates, namely glycoside, aminoglycoside, D-glucosamine, 2-O-methyl-L-fucose and galactoside, while markedly increasing glucose content; (2) Glycosides were the predominant carbohydrates secreted by T. ponticum roots, accounting for (79.63±8.19)% of the total relative abundance, whereas the remaining five carbohydrate types ranged from (3.40±0.53)% to (4.57±1.61)%; (3) Root-secreted carbohydrates exhibited significant differences between the control and light, moderate, or heavy salt stress treatments, but no significant distinctions were observed among the latter three treatments; (4) Soil electrical conductivity and nitrate nitrogen content were identified as key factors responsible for the down-regulation of the five carbohydrate types, while soil pH was the primary factor driving the up-regulation of glucose. CONCLUSION: T. ponticum can adapt to salt-stressed environments by regulating the content of carbohydrates secreted by its roots. Meanwhile, the abundance of carbohydrates secreted by the roots is also influenced by the soil properties.