The present invention relates to a Xanthine derivative as shown in formula (I), wherein, R is selected from: R 1 is selected from cyano or methoxycarbonyl; R 2 is selected from hydrogen and halogen atoms, a linear or branched C 1-6 alkyl group which is substituted or unsubstituted by 1 to 5 halogen atoms, a linear or branched C 1-6 alkoxy group which is substituted or unsubstituted by 1 to 5 halogen atoms; X and Y are each independently selected from C or N; and n is 0, 1, 2, 3 or 4.