The invention belongs to the technical field of subsidiary food processing, and particularly discloses a dioscorea opposite bean curd stick and a preparation method thereof. The dioscorea opposite bean curd stick is prepared from the following raw materials in parts by weight: 140 to 200 parts of dioscorea opposite, 60 to 100 parts of glycine max, 20 to 40 parts of pueraria lobata starch, 10 to 18 parts of sesamum indicum, 12 to 20 parts of medicago, 15 to 25 parts of cannabis sativa, 8 to 15 parts of euryale ferox, 8 to 16 parts of dried scallop, 4 to 12 parts of daucus carota, 18 to 30 parts of cane sugar, 1 to 3 parts of citric acid, 0.5 to 1.5 parts of a coagulator, and 0.5 to 1.5 parts of an antifoaming agent. The invention further discloses a preparation method of the dioscorea opposite bean curd stick. The method comprises the following steps: sequentially weighing the raw materials in parts by weight, pretreating the raw materials, feeding a formed bean curd stick into drying equipment to perform drying after pretreating, and then slicing, packaging and storing the dried and formed bean curd stick, so as to obtain a finished product. The preparation method is simple in technology, nutrition ingredients cannot be lost during preparation, and the dioscorea opposite bean curd stick is rich in nutrition, has aromatic flavor, is mellow and delicious, can meet the demands of different consumer groups, and has the efficacies of invigorating the spleen and stimulating the appetite, strengthening the constitution, reducing fever, lowering the evil fire, and reducing the blood pressure and flood fat.