The invention discloses a sulfadiazine tablet and a preparation method thereof, and belongs to the field of medicine. The sulfadiazine is prepared by adopting the following raw materials and auxiliary materials in parts by weight: 500 parts of sulfadiazine, 20 to 30 parts of isomalt, 5 to 10 parts of micro-crystal cellulose, 5 to 10 parts of wheat starch and 1 to 2 parts of stearic acid. The method is a method for directly tabletting powder and comprises the following steps: weighing stearic acid, crushing the stearic acid, filtering the crushed stearic acid by virtue of a 20-mesh sieve, weighing sulfadiazine, micro-crystal cellulose, wheat starch and an appropriate amount of crushed and filtered stearic acid, uniformly mixing to obtain a mixture, charging the remaining wheat starch and crushed and filtered stearic acid, and uniformly mixing; pressing the mixed powder by virtue of a tabletting machine to obtain tablets. The sulfadiazine tablet has the advantages that the powder direct-tabletting method is simple in process, the production cost is low, the releasing speed of the tablets is rapid, and the like and also solves the defects of poor mobility, large tablet weight difference, likeliness in fracturing and the like.