Abstract: In order to promote the high-value utilization of walnut green husk and provide a theoretical basis for its application as emulsifiers, foaming agents, and antioxidants, this study employed electron beam irradiation (EBI) at various doses (0, 5, 10, 25, and 50 kGy) to pretreat walnut green husk. The structural characteristics, physicochemical properties, and functional activities of the alkali-extracted polysaccharides were analyzed and compared following treatment. The results demonstrated that, compared to untreated walnut green husk polysaccharides, those subjected to low-dose EBI (5 kGy) exhibited the highest molar ratio of xylose (16.31%), molecular weight (80.43±2.37 kDa), particle size (145.99±4.64 nm), water/oil retention capacity (40.61 g/g, 83.08 g/g), and viscosity. Polysaccharides from GWH treated with moderate doses (10 and 25 kGy) showed significantly enhanced uronic acid content (35.69%±0.14%, 36.02%±0.37%), exceptional thermal stability (melting points of 84.87 ℃ and 86.63 ℃), emulsion activity (emulsification index: 14.41 m²/g and 13.64 m²/g), and ABTS⁺/DPPH free radical scavenging capacities (scavenging rates of 77.00% and 85.47% at 10 kGy, respectively). High-dose EBI (50 kGy) treatment of walnut green husk polysaccharides resulted in the highest foaming ability (56.67%), though other functional activities were somewhat reduced. Considering the properties of walnut green husk polysaccharides, this study concludes that 10 kGy is the optimal irradiation dose.