The present invention relates to a uridine phosphoramide prodrug, the preparation method therefor, and the medicinal uses thereof. The prodrug of the present invention is a chemical compound as shown in formula I, an optical isomer thereof or a pharmaceutically acceptable salt thereof. The prodrug of the present invention further comprises a solvate of the chemical compound shown in formula I, of an optical isomer thereof or of a pharmaceutically acceptable salt thereof. The prodrug of the present invention can treat viral infectious diseases, particularly hepatitis C viral infectious diseases.