The invention discloses a preparation method of cefpodoxime proxetil. In the method, a compound of formula II is used as an initial raw material, the intermediate compound of formula III is not separated during the process, and a crude product of cefpodoxime proxetil is synthesized by one step; and after that, a simple and easy recrystallization method is adopted for purifying the crude product of cefpodoxime proxetil to obtain cefpodoxime proxetil. In the preparation method disclosed by the invention, the yield is increased without reducing the quality, the obtained product has high purity, the synthesis path is simple, and the preparation method is suitable for industrial production.