The invention belongs to the medical technology field of anti-platelet aggregation effect, and provides a thienopyridine ester derivative containing nitrile group and its pharmaceutically acceptable salt possessing a structure shown in a general formula I, wherein R is a nitrile group. The invention also relates to a preparation method of the above compound, simultaneously, the present invention also discloses the medical composition using the compound or its pharmaceutically acceptable salt as an effective activity ingredient, and the applications as medicines for anti-platelet aggregation.