The antioxidant activity, hypoglycemic potential, and Alzheimer's therapeutic potential of Cyclobalanopsis glauca Shells were investigated in this study. The hydroxyl radical scavenging ability, DPPH radical scavenging ability, superoxide anion radical scavenging ability, and ABTS radical scavenging ability were used as an indicator for evaluating the in vitro antioxidant activity of Cyclobalanopsis glauca Shells Extract (CGSE). Then the α-glucosidase inhibitory ability of CGSE was evaluated by the fluorimetry assay, and the acetylcholinesterase (AChE) inhibitory ability of CGSE was evaluated by the modified Ellman method. Experimental results showed that CGSE had strong antioxidant activity, their IC₅₀ values of hydroxyl radical scavenging activity, DPPH radical scavenging activity, ABTS radical scavenging activity, and superoxide anion scavenging activity were (273.43±9.55), (8.31±0.08), (26.43±0.14) μg/mL, and (1 662.37±30.71) μg Trolox/g·DW, respectively. The IC₅₀ values toward α-glucosidase of CGSE was (24.81±1.99) μg/mL, which were significantly higher than that of positive control acarbose. CGSE also showed a certain AChE inhibitory ability with the IC₅₀ value of (422.29±25.26) μg/mL.