The invention discloses a cefazolin ester and a preparation method thereof as well as an oral antibiotic preparation. The molecular structural formula of the cefazolin ester is as shown in (I) in descriptions. The preparation method of the cefazolin ester comprises preparation of cefazolin ester acid-base salt and esterification reaction of cefazolin ester acid-base salt and carbonic acid-1-iodine ethyl ester ochxl cyclohexyl ester. The oral antibiotic preparation contains the cefazolin ester, the structural formula of which is as shown in (I). The cefazolin ester has the activity of cefazolin medicines and proper lipid/water partition coefficients and is suitable for drug administration of gastrointestinal tracts. The preparation method has the advantages that reaction conditions are easy to control, the process is simple, and the product yield is high. The oral antibiotic preparation has a good medicine effect and is safe and convenient to use; the occurrence rate of antibiotic misuse can be effectively reduced; and meanwhile, the selective range of oral antibiotics at home is expanded.