Abstract: Objective:To optimize the extraction technology of compound Cordyceps militaris(C. militaris)and study its hypoglycemic effect in rats with streptozotocin-induced type 1 diabetes mellitus. Method:Compound C. militaris was extracted by water decoction,and the extraction technology was optimized by single factor test and orthogonal test. Male Wistar rats were randomly divided into blank group,model group,and low-,medium- and high-dose compound C. Militaris group. The rats except those in the blank group were given streptozotocin for the establishment of type 1 diabetes mellitus. After the administration for 12 weeks,the body weight of rats in each group was measured,then the serum insulin,blood glucose,liver malondialdehyde,superoxide dismutase,glutathione peroxidase,triglyceride and total cholesterol were detected,and the morphological changes of kidney were examined by HE staining. Result:The optimal extraction technology of compound C. militaris was as follows:The ratio of material to liquid was 1:10 g/mL,compound C. militaris was extracted 3 times,1.5 h each time,and the extraction temperature was 70℃,The average extraction rate was 53.1%,the average polysaccharide yield was 5.1%,and the average total saponin yield was 1.3%. Compared with those in the model group,the related indexes of diabetic rats in compound C. militaris-treated groups were improved,in which the body weight,insulin level and GSH-Px activity of rats increased significantly(P<0.05),the SOD activity increased significantly(P<0.01),while the blood glucose value,the MDA level in the liver,and the TG and TC levels in the kidney increased significantly(P<0.01)in the high-dose compound C. militaris group. The renal injury degree of rats was significantly improved in each compound C. militaris-treated group. Conclusion:The extraction technology of compound C. militaris was optimized,and the extract by the optimal technology had a significant hypoglycemic effect in rats with streptozotocin-induced type 1 diabetes mellitus.