To study the efficacy and mechanism of Gegen Qinlian Decoction(GQD)in the treatment of diabetic osteoporosis rats. Methods:A total of 60 female SD rats were randomly divided into 3 groups. The control group did not receive any treatment, and the remaining 40 were intraperitoneally injected with streptozotocin 35 mg/kg once to establish a rat model of diabetes. GQD group:According to the crude drug amount 10 g/kg, GQD was intragastrically administered to the rats. The model group was intragastrically administered with 0.9% NaCl for 12 weeks, and the rats, fasting insulin level(Fins), fasting blood glucose(FBG),insulin sensitivity index(ISI)and hormone resistance index(HOMA-IR)were detected. RT-PCR and Western Blot were used to detect the expression of BMP-2/Smad pathway in vertebral body, and the bone mineral density, bone calcium content, biomechanical properties and HE staining were further determined. Results:Compared with the control group, the HOMA-IR, the FBG level in rats of model group increased, and the Fins and ISI decreased(P<0.05).Compared with the model group, the HOMA-IR, the FBG level decreased, and the Fins and ISI were increased in the GQD group(P<0.05).Compared with the control group, the expression of BMP-2,Smad1,Smad4 gene and protein expression in the vertebral body of the model group was significantly lower(P<0.05).Compared with the model group, the expression of BMP-2,Smad1,Smad4 gene and protein expression in the vertebral body of the GQD group were significantly increased(P<0.05).Compared with the control group, the bone mineral density, bone calcium content, ultimate load, ultimate stress and elastic modulus of the model group were significantly lower(P<0.05).Compared with the model group, the bone mineral density, bone calcium content, ultimate load, ultimate stress and elastic modulus of the GQD group were significantly increased(P<0.05),HE staining showed that osteoporosis was alleviated in rats after treatment with Gegen Qinlian decoction. Conclusion:GQD can reduce the blood glucose level of diabetic osteoporosis rats and alleviate insulin resistance, and may play a role in the treatment of diabetic osteoporosis by increasing the BMP-2/Smad pathway.