Abstract: In order to study the regulatory effects of ethylene on the salt stress response of soybean and promote the application of ethylene in high-efficiency soybean cultivation, the salt-tolerant soybean variety Qihuang 34 was used as experimental materials. We used the method of hydroponics, exogenous added of 1-aminocyclopropane-1-carboxylic acid（ACC） and then set NaCl stress treatment. The effects of salt treatment on the gene expression of key rate-limiting enzymes of ethylene synthesis, ethylene on the seedling morphogenesis, osmotic regulation system and oxidation-reduction system were measured to analyse the regulatory effect of ethylene on soybean salt resistance. The results showed that NaCl treatment significantly increased the expression of GmACS1,GmACS2 and GmACS6, the key rate-limiting enzymes of ethylene synthesis at different time points, promoted the evolution of ethylene. Under salt stress, exogenous ACC treatment accelerated the senescence of soybean leaves, decreased dry matter accumulation of shoots and roots, leaf chlorophyll content. Exogenous addition of ACC significantly increased the content of Na⁺, K⁺, Na⁺/K⁺ and MDA content, and decreased the content of proline under salt stress. In addition, exogenous addition of ACC significantly increased O₂·^- release and the expression of NADPH oxidase GmRbohA and GmRbohB genes in soybean leaves, but decreased POD enzyme activity under NaCl stress. The results showed that ethylene negatively regulated soybean salt tolerance by regulating ROS homeostasis and Na⁺/K⁺ equilibrium.