Hemorrhagic transformation (HT) is a serious complication that can occur as a result of thrombolytic therapy following ischemic stroke (IS), and it poses significant limitations on the clinical application of recombinant tissue plasminogen activator (rt-PA). Unfortunately, there are currently no effective interventions available for HT in clinical practice. Therefore, there is an urgent need for stable and reliable experimental animal models to elucidate the pathogenesis of HT and develop effective intervention strategies. This study presented a protocol for establishing a mouse model of HT induced by acute hyperglycemia combined with transient focal ischemia (tMCAO). Male C57BL/6J mice were injected with 30% glucose to induce hyperglycemia and then subjected to 60 min of tMCAO with reperfusion. The infarct volume, integrity of the blood-brain barrier (BBB), and degree of intracranial hemorrhage were assessed at 24 h after MCAO. The results showed that glucose injection led to transient hyperglycemia (14.3-20.3 mmol/L), which significantly increased both the infarct volume and the incidence of HT. Hematoxylin-eosin (H&E) staining indicated significant hemorrhagic lesions within the infarction zone in hyperglycemic mice. Additionally, hyperglycemic mice exhibited aggravated BBB disruption, as shown by more severe leakage of Evans blue (EB) and FITC-Dextran. In conclusion, acute hyperglycemia reliably and consistently resulted in macroscopic HT in a mouse model of tMCAO. This reproducible model offers a valuable tool for investigating the pathological mechanisms of HT and developing corresponding therapeutic interventions.