Abstract: Objective: To develop a new technique for the steady-state macro-preparation of Lycium barbarum polysaccharides (LBPs) and investigate the structural features and in vitro and in vivo hypoglycemic activities of the obtained LBPs. Methods: LBPs were prepared by an integrated technique of subcritical pretreatment, high-speed shear-assisted extraction, ultrafiltration membrane separation, and purification with macroporous resins. They were analyzed for relative molecular mass, monosaccharide composition, and structural features. The hypoglycemic activity of LBPs was evaluated using the α-glucosidase and α-amylase activity inhibition assays, the oral glucose tolerance test in normal mice, and the alloxan-induced diabetic mice model. Results: LBPs were acidic heteropolysaccharides predominantly comprising arabinose (35.73%), glucose (31.20%), and galactose (23.50%), which had block and chain structures in aqueous solution. The results of the enzyme activity inhibition experiments demonstrated that α-glucosidase inhibition by 10 mg/mL LBPs was 86.72%±1.51% and the inhibition of α-amylase by 22.5 mg/mL LBPs was 80.39%±1.42%. The results of hypoglycemic experiments in vivo demonstrated that LBPs significantly improved glucose tolerance and reduced blood glucose levels in mice. After administering 100 and 500 mg/kg LBPs to alloxan-induced diabetic mice for 2 h, their blood glucose levels decreased by 22.73% and 33.00%, respectively. Conclusion: LBPs obtained using the new steady-state macropreparation technology demonstrated good hypoglycemic activity in vitro and in vivo. This lays a foundation for the development of LBP-based hypoglycemic adjunctive health foods.