The invention discloses sulfadiazine starch capsules and a preparation method thereof, belonging to the field of medicine. The sulfadiazine starch capsules prepared in the invention comprise an active ingredient sulfadiazine and one or more of diluent, lubricant, flow aid, disintegrating agent and wetting agent and further comprise starch hollow capsules which can be quickly disintegrated in intestines and stomach. Compared with sulfadiazine tablets, the sulfadiazine starch capsules disclosed by the invention can improve the stability of sulfadiazine, delay the release of sulfadiazine and realize site-specific delivery. Compared with sulfadiazine gelatin capsules, the sulfadiazine starch capsules can effectively avoid the problems of the gelatin capsules such as overproof heavy metals, overproof microorganisms and immunogenicity. The sulfadiazine starch capsules disclosed by the invention have the advantages of convenience in taking, good curative effect, high bioavailability, low toxic and side effects, safety without pollution and the like.