Abstract: In order to provide theoretical support for diabetes prevention and therapy, this study investigated the regulatory effect of Berberis dasystachya Maxim. Polysaccharide (BDP) on glucose and lipid metabolism in streptozotocin (STZ)-induced diabetic rats. Diabetic model rats were randomly assigned to the model control group, low-dose polysaccharide group (BDP-L, 10 mg/kg), mid-dose polysaccharide group (BDP-M, 200 mg/kg), and high-dose group (BDP-H, 400 mg/kg). Blood lipid levels, lipid metabolic enzyme activity, and antioxidant enzyme activity served as evaluation markers. Results showed that after 28 days of administering yellow thorn polysaccharide, the BDP-treated groups exhibited significantly (P<0.05) lower blood glucose and lipid levels compared to the model group, with a remarkable 39.16% reduction in blood glucose in the high-dose group (P<0.01). In contrast, serum insulin levels and hepatic glycogen (HG) levels increased in the BDP-treated groups (P<0.05 or P<0.01), with a 1.28-fold increase in serum insulin (P<0.01) and an 89.79% increase in HG (P<0.01) in the high-dose group. Furthermore, compared to the model group, serum and pancreatic levels of catalase (CAT), superoxide dismutase (SOD), and reduced glutathione (GSH-Px) were significantly elevated (P<0.05 or P<0.01), while malondialdehyde (MDA) levels were considerably reduced (P<0.05) in a dose-dependent manner following BDP treatment. In conclusion, BDP effectively improved glucolipid metabolism in diabetic rats by alleviating oxidative stress, ultimately safeguarding pancreatic β-cell integrity in type I diabetes.