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 and diseases caused by hepatitis B virus, the definition of each substituent in the general formula (I) being the same as the definition in the specification.