In acute myocardial infarction (AMI) emergency percutaneous coronary intervention (PCI), in-stent thrombosis is a relatively common complication after coronary interventional procedures, but the occurrence of it may have adverse consequences if it is not treated promptly. Platelet glycoprotein (GP) IIb/IIIa receptor antagonists play an antithrombotic role by blocking the binding of fibrinogen receptor to the GPIIb/IIIa complex, inhibiting the final pathway of platelet aggregation, and effectively inhibiting platelet aggregation. In our hospital, in recent years, the combined application of domestic platelet IIb/IIIa receptor antagonist (Xinwenning) treatment has achieved good therapeutic effect. The intravenous push dose and drip rate are calculated according to the patient’s body weight. Patients in the clinic were treated with aspirin, poliovir, and low-molecular heparin, except for contraindications. In unstable angina or non-Q-wave myocardial infarction, tirofiban hydrochloride injection in combination with heparin was infused intravenously at a starting 30-minute drip rate of 0.4 μg/kg/min, with a maintenance drip of 0.1 μg/kg/min after completion of the starting infusion. In studies validating efficacy, tirofiban hydrochloride sodium chloride injection (Synvonin) titrated in combination with heparin generally lasted at least 48 hours and up to 108 hours. The drip may be continued during angiography and for 12-24 hours after angioplasty. PATIENTS WITH SEVERE RENAL INSUFFICIENCY: In patients with severe renal insufficiency (myohepatic clearance less than 30 ml/min), the dose of this product should be reduced by 50%. Other patients: Dose adjustments are not recommended for elderly patients or female patients. Emergency PCI is preferred for the treatment of acute ST-segment elevation myocardial infarction.In-stent thrombosis usually occurs after implantation of the stent, and the incidence of thrombosis is about 1-1.5% with adequate antiplatelet and anticoagulant medication.Thrombosis after PCI may be related to a variety of factors, such as incomplete apposition of the stent to the vessel wall, characteristics of the stent surface and coating substances, the hypercoagulable state of the patient, the unstable plaque, lesion length, and other factors. plaque, and lesion length, as well as being closely related to platelet activity and the formation of platelet-rich thrombi. Platelet activation, adhesion and aggregation are the key initiating steps for arterial thrombosis on the ruptured surface of plaques, and thrombosis is the main pathophysiological problem in acute coronary ischemic syndrome, i.e., unstable angina and infarction, as well as in ischemic complications of the heart after coronary angioplasty. Tirofiban hydrochloride is a novel reversible nonpeptide platelet GPIIb/IIIa receptor antagonist, which is the fastest acting and most selective platelet inhibitor at present. It can competitively inhibit the binding of fibrinogen and platelet GPIIb/IIIa receptor, and dose-dependently inhibit platelet aggregation, prolong bleeding time, and inhibit thrombosis in vitro. It has an inhibitory effect on ADP and collagen-induced platelet aggregation, and the hemostatic function of platelets returns to normal within 30-90 minutes after stopping infusion, which indicates that tirofiban hydrochloride has no direct long-term effect on platelets, so it is safe and has few serious bleeding complications. We need to accumulate experience in the current clinical application, which can effectively prevent in-stent thrombosis during and after emergency PCI and reduce the occurrence of fatal cardiovascular events.