Spermatogenic dysfunction is a common complication in men with diabetes and is the most important manifestation of diabetes-related male reproduction damage. Astragalin (AG) is one of the main flavonoids from Cuscuta chinensis, which has rich pharmacological activities. This study aimed to establish whether AG may contribute to the recovery from spermatogenic dysfunction. AG (3.3, 10 and 30 mg/kg) and Clomiphene (5 mg/kg) were orally administered to streptozotocin-induced diabetic male mice for 8 weeks. After the experiments performed, reproductive organs, sperm parameters and histomorphological changes were analysed. Antioxidant and anti-inflammatory capacity were estimated in testicular tissues. The results revealed that AG significantly improved the reproductive organs, sperm parameters and testicular morphology to different degrees in diabetic mice. Nitric oxide (NO) and malondialdehyde (MDA) levels were significantly reduced, and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), markedly increased in the testicular tissue after AG was administered. Interestingly, AG also downregulated the protein expressions of tumour necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) in testes. In conclusion, AG is a potential beneficial agent to protect diabetic-induced spermatogenic dysfunction in male mice by increasing antioxidant enzymes activities and inhibiting inflammation.