The invention discloses a retarder combining Chinese medicines and western medicines and used for preventing and curing the rabbit coccidiosis and a preparation method thereof, pertaining to the technical field of prevention and cure with the drug of poultry and livestock parasite. The retarder comprises ingredients with portions by weight: 2 to 5 portions of antifeverile dichroa root, 3 to 6 portions of abrotanum, 2 to 5 portions of sophora flavescens, 1 to 3 portions of pulsatilla chinensis, 1 to 3 portions of radix bupleuri, 1 to 3 portions of rhizoma imperatae, 1 to 3 portions of liquoric root, 0.01 to 0.05 portions of diclazuril, 8 to 10 portions of porous starch and 0.001 to 0.003 portions of chitosan. The ingredients are prepared by the steps of soaking in ethanol and Soxhlet extraction, followed by soaking in water and Soxhlet extraction, mixing, absorption and combination of extract and diclazuril as well as porous starch and chitosan, and regulation of medicinal powder quality, etc. The results from the experiments show that the egg reduction rate for the rabbit coccidiosis is 99.2 percent; in addition, the retarder of the invention is mainly applied to the prevention and cure of the rabbit coccidiosis.