Objective: This study aimed to study the changes of active components in irradiated Rhodiola rosea extracts (RRE) and their hypoglycemic effect. Methods: Rhodiola rosea was irradiated with 60Co-γ rays at doses of 5, 10, 20 and 30 kGy, respectively. High performance liquid chromatography (HPLC) was used to analyze RRE compounds before (0 kGy) and after irradiation. The type 1 diabetic mouse models established by intraperitoneal injection of Streptozotocin (STZ) were given a gavage. The body weight, fasting blood glucose, food intake and water intake of mice were measured regularly. Oral glucose tolerance was measured on the last day, after dissection, organ coefficient, serum total cholesterol (TC), glycosylated hemoglobin (GHb), total triglyceride (TG), malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) were measured. Results: The content of salidroside in RRE was significantly decreased after irradiation (P＜0.05), and the content of loxavir was significantly increased at 5, 10 and 20 kGy (P＜0.05). Tyrosol was detected at 20 kGy. Compared with the model group, the body weight of mice was given a gavage with irradiation RRE was increased, the food intake, water intake and blood glucose level decreased, and the food utilization rate increased significantly (P＜0.05). The levels of TC, GHb, TG and MDA were significantly decreased (P＜0.05), while the activities of SOD and CAT were significantly increased (P＜0.05). The phenomenon of organ swelling was improved, and the effect was better at 20 kGy, and there was a significant difference with other irradiation doses (P＜0.05). Conclusion: The composition and content of RRE compounds changed after irradiation, and RRE can reduce the level of diabetes in type 1 diabetic mice before and after irradiation. The irradiation dose of 20 kGy is effective.