The invention discloses an orally disintegrating tablet for preventing and treating and a preparation process thereof, and belongs to the field of veterinary drug preparations. The orally disintegrating tablet comprises the following components in parts by weight: 0.01-0.2 parts of pyrimethamine, 0.1-0.2 parts of sulfamethoxazole, 0.03-0.04 parts of trimethoprim, 20-30 parts of disintegrating agent, 15-40 parts of filler, 1-2 parts of lubricant, 1-5 parts of flow aid, 2-5 parts of adhesive, 1-2 parts of surfactant, and 1-2 parts of flavoring agent. According to the orally disintegrating tablet, pyrimethamine, sulfamethoxazole and trimethoprim are combined to prepare the orally disintegrating tablet, the principle of drug combination is accorded, the drug synergism can be improved, and the administration times can be reduced. The preparation is an orally disintegrating tablet, has the characteristics of simple production, accurate dosage and high bioavailability, has a key point that the administration means of medicine is changed, and can be used for solving the problem that a pet cat cannot be easily subjected to injection administration and oral tablet administration. The orally disintegrating tablet can be taken without water, does not need swallow, can be disintegrated in the oral cavity when encountering saliva, and can be absorbed by virtue of oral mucosa.