【Objective】 This study aimed to examine the effects of salt and flooding interactions on the growth and physiological responses of Salix hybrid, focusing on the physiological mechanisms underlying its tolerance to salt-flooding stress. 【Method】One-year-old Salix hybrid cuttings were subjected to two water conditions—normal watering and flooding—and four salinity levels (0%, 0.2%, 0.4%, and 0.6% mass fraction of NaCl), with normal water without salt serving as the control. Samples were collected at six time points (3, 10, 17, 24, 41, and 60 days post-treatment) to measure seedling height, root collar diameter, biomass, and physiological indicators, including superoxide dismutase (SOD), peroxidase (POD) activities, malondialdehyde (MDA), soluble sugar (SS), soluble protein (SP), proline (Pro) content, root vigor, and chlorophyll content. These parameters were analyzed to evaluate the effect of salt-flooding interactions on the growth and physiology of the Salix hybrid. 【Result】Low salinity under flooding conditions promoted seedling elongation, whereas high salinity under flooding inhibited growth. Relative electrical conductivity and MDA levels exhibited a continuous increase under combined salt and flooding stress. Antioxidant enzyme activity was more pronounced under the combined stress than under individual stress conditions, with SOD activity responding more rapidly than POD activity. Compared to salt stress alone, SS content significantly decreased on 24 days, SP content increased significantly on 17 days, and Pro content showed an initial increase, followed by a decline and subsequent recovery. Root vigor was higher under salt-flooding stress than that under salt stress alone, while chlorophyll content decreased significantly and remained lower than that under single salt stress.【Conclusion】The Salix hybrid demonstrated a robust osmoregulatory and protective enzyme system in response to salt-flooding stress, which played a critical role in its adaptive capacity. Biomass, MDA levels, and root vigor were identified as key indicators for assessing water and salt tolerance. The salinity tolerance threshold was determined to be 0.65% (111.22 mmol/L) under normal water conditions and 0.42% (71.87 mmol/L) under flooded conditions, indicating the Salix hybrid’s strong salinity tolerance. This study provides theoretical and practical insights into the physiological mechanisms of the Salix hybrid under salt-flooding stress, offering valuable guidance for its cultivation in saline and waterlogged environments.