【Objective】 Echinochloa frumentacea is a high-yielding and high-quality forage grass that can be used as both forage and feed. The soil salinization in the planting area seriously affects its normal growth, development, and yield. Epioilcanola (EBR) is an active analogue of brassinosteroid (BRs) plant hormones. To offer a theoretical foundation for the application of EBR to the production of E. frumentacea on salinized soils, it is necessary to investigate the regulatory effects of this lactone on the salt tolerance of E. frumentacea as well as its mode of action to mitigate the salt stress damage. 【Methods】E. frumentacea variety 'Ningji No.1' seedlings were employed as test subjects. After determining the appropriate concentrations of salt stress, separate treatments were set up using salt (150 mmol/L NaCl) and various concentrations of EBR (1, 10, and 100 μg/L). The hydroponic test was used to examine changes in growth indexes, physiological stress resistance indexes, photosynthesis indexes, ionic homeostasis, encoding the signaling pathway of salt allergy (SOS), and the expression of genes related to antioxidant enzymes in the seedling under each treatment. 【Results】 (1) E. frumentacea seedlings treated with salt stress alone showed significantly slower growth (plant height, root length, biomass, etc.) when compared to the control; leaf photosynthesis indexes (chlorophyll content and chlorophyll fluorescence parameter Y(Ⅱ), Fv'/Fm', ETR, qP, etc.); osmotic regulating substance content (proline content, soluble Proline content, soluble protein content); and antioxidant enzyme (SOD, POD, CAT, APX) activities were significantly reduced; root K+, Ca2+, and Mg2+ contents were significantly decreased, but root Na+ content was significantly increased; leaf reactive oxygen species (superoxide anion, hydrogen peroxide) content and cell membrane permeability (malondialdehyde content, relative conductivity) were significantly increased; in the meantime Nevertheless, the use of EBR therapy alone did not significantly impact the majority of the aforementioned indices.(2) After salt stress, E. frumentacea adverse alterations in the aforementioned indices were effectively reduced by spraying various doses of EBR treatments; the greatest results were obtained with 10μg/L EBR treatment (SS+E10).(3) Compared with the salt stress treatment alone, the growth indexes as well as the content of osmoregulatory substances, antioxidant enzymes and photosynthesis indexes of E. frumentacea seedlings treated with SS+E10 were significantly improved, the cell membrane permeability and reactive oxygen species content of leaves were significantly reduced; the intracellular Na+ accumulation in the root cells was significantly reduced, and the content of K+, Ca2+ and Mg2+ in the root system was significantly increased, and the homeostatic balance of Na+/K+ ions was regulated; and the expression of the genes related to the SOS signaling pathway and antioxidant enzymes was significantly up-regulated. 【Conclusion】 Foliar spraying of EBR significantly up-regulated the expression of SOS signaling pathway and antioxidant enzyme-related genes in the leaves of E. frumentacea seedlings under salt stress, enhanced their antioxidant and osmoregulatory abilities, reduced the degree of membrane lipid peroxidation and cell membrane damage, maintained the balance of ionic homeostasis in the root system, and effectively protected the photosynthesis and normal growth of seedling leaves, which had a significant regulatory effect on the promotion of salt tolerance in E. frumentacea and had the best effect with the treatment of 10μg/L EBR.