The invention discloses a preparation method of a mildew-proof shaving board. The preparation method comprises the following steps of carrying out heat treatment on wood shavings, sending the wood shavings into a stirrer, spraying a mixture of a golden cypress extracting solution, an andrographis paniculata extracting solution, a calyx seu fructus physalis extracting solution and a fructus cnidiiextracting solution while stirring the wood shavings, drying the wood shavings until the water content is 3.4 wt%-5.5 wt%, and gluing the wood shavings, wherein the raw material of a used adhesive comprises soybean glue, phenolic resin, PVAc latex, melamine glyoxal resin, didodecyl dimethyl ammonium chloride, a nano zirconium phosphate silver-loaded antibacterial agent, a litsea cubeba extract, amulberry leaf extract, a Biebersteinia heterostemon extract, dried orange peel essential oil, sepiolite, nano cellulose, hexamethylenetetramine and diphenylmethane diisocyanate; and laying the pretreated wood shavings subjected to gluing into a plate blank, and carrying out pre-pressing, hot-pressing, cooling, edge cutting and sanding to obtain the mildew-proof shaving board. The preparation method of the mildew-proof shaving board is simple in process, and the obtained shaving board is excellent in antibacterial and mildew-proof performance, good in water resistance and long in service life.