Abstract: This study systematically investigated the potential of walnut male flowers (WMF) as a functional ingredient in steamed buns by evaluating the impact of WMF incorporation at five graded levels (1%, 2%, 3%, 4%, and 5% w/w, based on flour weight) on both quality attributes and nutritional functionality. Quality parameters included specific volume, height-to-diameter ratio, instrumental color, texture profile analysis, microstructural porosity, and overall sensory acceptability. Nutritional functionality was assessed through antioxidant capacity, in vitro starch digestibility, and predicted glycemic response. Results demonstrated WMF addition significantly affected all quality indicators (P<0.05). The 2% WMF group had the highest specific volume 2.74 cm³/g and a porosity of 28.03%, whereas the 1% WMF group had the highest sensory score (80.4). With increasing WMF addition, the total polyphenol and flavonoid contents increased, reaching 4.55 and 7.5 times those of the control group, respectively. In terms of antioxidant capacity, the 5% WMF addition increased the DPPH and ABTS⁺ free radical scavenging rates to 3.33 and 4.36 times those of the control group, respectively, and the ferric reducing antioxidant power (FRAP) increased to 3.75 times that of the control group. Furthermore, 5% WMF addition elevated the resistant starch (RS) content to 2.28 times that of the control and reduced the estimated glycemic index (EGI) from 75.16 to 68.18. In conclusion, moderate WMF addition improves the sensory quality of steamed bun and significantly enhances its antioxidant and slow-digestion properties, demonstrating promising potential for developing functional foods with blood glucose-lowering effects.