The invention relates to an isoflavone derivative and a preparation method and application thereof, which belong to the field of chemical medicaments. The technical problem solved by the invention is to provide the isoflavone derivative and the preparation and the application thereof. The isoflavone derivative has a structural formula as shown by (I), wherein R1 and R2 in the structural formula are C1-C5 alkyls. The isoflavone derivative has a significant effect of resisting Coxsackie viruses, can be used for preparing medicaments for resisting the Coxsackie viruses, and has an intensive application prospect.