Aim To investigate the effect of ticagrelor on platelet reactivity and short-term prognosis in patients with unstable angina pectoris during perioperative period of percutaneous coronary intervention (PCI). Methods 424 patients with unstable angina pectoris were enrolled. They were randomly divided into two groups:(1)ticagrelor group (n＝212):treated with ticagrelor (load dose 180 mg, maintenance dose 90 mg, twice a day, oral); (2)clopidogrel group (n＝212):treated with clopidogrel (load dose 300 mg, maintenance dose 75 mg, once a day, oral). PCI was successfully performed in both groups, and domestic Firebird rapamycin drug-eluting stents were selected as stents. The platelet reactivity, cardiac troponin I (cTnI), a marker of myocardial injury during perioperative period of PCI, and the occurrence of adverse events 90 days after PCI were observed in two groups. Results There was no significant difference in cTnI level between the two groups after PCI (P＞0.05). The platelet aggregation rate induced by arachidonic acid and adenosine diphosphate in ticagrelor group was lower than that in clopidogrel group (P＜0.05). The ratio of high platelet reactivity induced by adenosine diphosphate in ticagrelor group was lower than that in clopidogrel group (P＜0.05). The incidence of recurrent myocardial ischemia within 90 days after PCI in ticagrelor group was lower than that in clopidogrel group (5.19% vs 16.04%, P＜0.05). There was no significant difference in hemorrhagic events between the two groups (P＞0.05). Conclusion Ticagrelor does not reduce the incidence of myocardial injury after PCI, but it has a stronger antiplatelet effect than clopidogrel, and reduces the incidence of recurrent myocardial ischemia events after PCI without increasing the risk of bleeding.