Cephalosporin analog antibiotic preparation method

The present invention relates to new method of preparing cephalo antibiotic. The new preparation process includes first acidylating the C7 place of initial material 7-amino-3-methylol cephaloalkanoic acid, the subsequent esterifying the C2 place carboxyl radical with corresponding ester radical, and final functionating the C3 place of the product. The process of the present invention has less reaction steps, raised total synthesis efficiency, low cost and reduced environmental pollution.