The invention relates to a tenofovir prodrug and pharmaceutical uses thereof. In particular, the invention relates to a compound as shown in general formula (I): and its isomer, pharmaceutically acceptable salt, hydrate or solvate, as well as their uses in preparing drugs for treating viral infectious diseases, especially HIV infection, hepatitis B, or diseases caused by hepatitis B virus, wherein the definition of each substituent in the general formula (I) is as defined in the specification.