The present invention provides a novel phillygenin glucuronic acid derivativeshown as a general formula(I).(see formula I)wherein, R1=H, R2=CnH2n+1, R3=CnH2n+1 or R1=CnH2n+1, R2=CnH2n+1, R3=H or R1-R2=-CH2-, R3=CnH2n+1;n=1-30. The present invention further relates to a preparation method of thecompound, a pharmaceuticalcomposition taking the compound as an active ingredient, as well asapplication of the compound in thepresent invention in antiviral diseases.