Prodrugs based on gemcitabine structure shown in formula (I) as well as their synthetic method and application are disclosed in the present invention, wherein the definitions for the groups of a, b, c, d, E, Z and V are described in the specification. By modifying the N4 group, the solubility, the bioavailability and the organ specificity of the prodrugs are improved. Therefore, the fast metabolism problem is overcome for the produced prodrugs compounds. Intestinal toxicity induced by gemcitabine is decreased. Thereby, the prodrugs can be delivered by oral administration in clinics and further improve their anti-tumor, anti-cancer, anti-infection and diffusion preventing capability, and can also specifically act on liver or colon. The synthetic method is simple and adapted to industrial production.