Both qingke and oats are rich in β-glucans， yet systematic comparisons of β-glucan structural characteristics， physicochemical properties， and functional attributes across species and cultivars remain limited. This study investigated blue qingke β-glucan， commercially available qingke β-glucan， and oat β-glucan using FT-IR spectroscopy， rheometry， and other techniques to compare their structural features， physicochemical properties， and bioactivities. FT-IR characterization revealed that all three β-glucans share similar plant polysaccharide structures with β-configurations， yet exhibit distinct molecular architectures. Structural differences were correlated with variations in physicochemical and functional properties. Results showed that blue qingke β-glucan contained fewer hydroxyl groups and lower protein content， but a greater diversity of functional groups. Compared to the other two β-glucans， blue qingke β-glucan demonstrated superior oil-holding capacity (3.62 g/g±0.14 g/g)， foaming ability (180%±8.66%)， and foam stability (49.1%±0.78%)， along with lower emulsifying activity (64.44%±1.80%) but higher emulsion stability (93.71%±4.96%). Its water-holding capacity (3.65 g/g±0.10 g/g) and solubility (89.95 g/100 g±0.09 g/100 g) were significantly lower than those of the other β-glucans. Rheological analysis indicated that all three β-glucan solutions exhibited shear-thinning pseudoplastic behavior and gel-like solid characteristics. Furthermore， blue qingke β-glucan showed enhanced free radical scavenging capacity against both ABTS+ (17.03%±0.52%) and DPPH (31.4%±0.52%). This study provides theoretical foundations for practical applications of qingke and oat β-glucans in food production and offers novel insights for developing functional foods.