Objectives: To evaluate the effect of tirofiban injection on vascular endothelial function, cardiac function, inflammatory cytokines and other indicators in patients with acute myocardial infarction after emergency PCI and its clinical significance. Methods: Eighty patients with acute myocardial infarction admitted to Affiliated Hospital of Hebei University from March 18, 2020 to October 18, 2020 were enrolled and randomly divided into two groups: the experimental group and the control group, with 40 cases in each group. Patients in both groups underwent PCI. Patients in the control group were given oxygen inhalation, monitoring, and basic medications for myocardial infarction, such as nutritional myocardial drugs, statins, aspirin, nitrates, clopidogrel, and beta-blockers. In contrast, patients in the experimental group received tirofiban 10 ug/kg intravenously over 5min immediately before PCI in addition to basic treatment, and then tirofiban 0.1 ug/(kg/min) was pumped via intravenous pump postoperatively for 48 hour. The changes of vascular endothelial function, cardiac function and adverse drug reactions (ADRs) in the two groups before treatment, one week and one month after treatment, as well as changes of inflammatory cytokines such as CRP and IL-6 in the two groups before and after treatment were compared and analyzed. Results: Compared with the control group, FMD, NO, ET-1 and other indexes in the experimental group were significantly improved one week and one month after treatment, with statistically significant differences (p<0.05). BNP, LVEDD, LVEF and additional indexes in the experimental group were significantly lower than those in the control group at one week and one month after treatment, with statistically significant differences (p=0.00). Moreover, the incidence of ST-segment fallback > 70% in the experimental group was 72.5% after treatment, which was significantly better than that of 47.5% in the control group, with a statistically significant difference (p=0.03). CRP and IL-6 in the experimental group were significantly lower than those in the control group after treatment, with a statistically significant difference (p=0.00). There was no statistical significance in the incidence of ADRs between the two groups after treatment (p=0.42). Conclusion: Tirofiban injection after emergency PCI is a beneficial treatment regime for patients with STEMI. With such a treatment regime, cardiac function and vascular endothelial function of patients can be dramatically improved, coronary blood supply will be ameliorated, inflammatory cytokines can be reduced, and no significant increase can be seen in the incidence of adverse reactions.