Objective: To observe the effect of ticagrelor for non-ST-segment elevation acute coronary syndrome after percutaneous coronary intervention (PCI). Methods: A total of 200 patients with non-ST-segment elevation acute coronary syndrome after PCI were enrolled in this study.And the patients were randomly divided into the observation group (18 months treatment group, 100 cases) and control group (12 months treatment group, 100 cases) according to the digital table.The control group was given dual antiplatelet therapy (DAPT) for 12 months, and then, suspended the usage of ticagrelor.The observation group was treated by DAPT for 18 months.The major adverse cardiovascular events (MACCE) and the secondary end point events were observed. Results: The incidence rate of MACCE between the two groups had no statistically significant difference (χ²=0.298, P=0.862). And there was no statisticallysignificant difference in the incidence of the secondary end point events between the two groups (χ²=1.963, P=0.375). Conclusion The usage of DAPT beyond or equal 12 months doesn't reduce the incidence of MACC and it will not increase the blooding rate.The use of DAPT (aspirin and ticagrelor) should be used less than 12 months.