To observe the effect of Liqi Huatan Huoxue formula on the degree of coronary microvascular thrombosis obstruction in rats with coronary microcirculation disorder(CMD)，and to explore its mechanism in protecting vascular endothelial function.Methods:SPF-grade Sprague Dawley(SD) rats were randomly divided into a blank group，a sham operation group，and a modelling group.The model of coronary microcirculation disorder in rats was established by injecting sodium laurate 1 mL/kg(mass concentration 1 g/L) into the left ventricle through the apical part of the heart.After 24 hours of modeling，5 rats were randomly sacrificed，the hearts were extracted，and myocardial tissue samples were taken.The HE-stained pathological sections revealed thrombosis formed in the coronary microvascular of rats，confirming successful modelling.The remaining modelled rats were randomly divided into a model group，low-，medium-，and high-dose Liqi Huatan Huoxue formula groups，a nicorandil group，as well as a valsartan group.After 4 weeks of continuous gavage，the degree of coronary microvascular thrombosis obstruction，serum endothelin-1(ET-1) level，and serum nitric oxide(NO) content were observed in each group.Results:Compared with the model group，the degree of coronary microvascular thrombosis obstruction was improved in the low-，medium-，and high-dose Liqi Huatan Huoxue formula groups.Additionally，the level of creatine kinase isoenzyme(CK-MB)(P<0.001) and ET-1 concentration(P<0.05) were significantly reduced，while the catalase(CAT) activity(P<0.001)，glutathione(GSH) content(P<0.001)，NO concentration(P<0.05)，NO/ET-1 ratio(P<0.05)，and endothelial nitric oxide synthase(eNOS) content(P<0.05) were significantly increased，inhibiting myocardial tissue and endothelium apoptosis in CMD rats.Conclusion:Liqi Huatan Huoxue formula can improve myocardial tissue histopathological damage and vascular endothelial function，reduce coronary microvascular thrombosis formation，inhibit apoptosis，and improve coronary microvascular function in CMD rats.