The invention discloses a pumpkin and rhizoma dioscoreae compound beverage and a preparation method thereof and belongs to the technical field of production of fruit and vegetable beverages. The beverage is prepared from the following raw materials in parts by weight: 5 to 8 parts of pumpkin powder, 4 to 8 parts of rhizoma dioscoreae powder, 1 to 2 parts of corn meal, 3 to 6 parts of isomaltitol,2 to 5 parts of sorbitol, 0.3 to 0.6 part of a compound stabilizer and 70 to 85 parts of cold boiled water, wherein the compound stabilizer is prepared from carrageenan, xanthan gum and sodium carboxymethyl cellulose; the content of the components is as follows in parts by weight: 0.1 to 0.2 part of the carrageenan, 0.05 to 0.1 part of the xanthan gum and 0.15 to 0.3 part of the sodium carboxymethyl cellulose. A technological flow of the preparation method comprises the following steps: dissolving the raw materials, boiling, naturally cooling, finely grinding, gelatinizing, blending in a constant volume, cooling, homogenizing, carrying out ultrahigh-temperature sterilization, carrying out sterile filling and packaging a finished product and storing. According to the pumpkin and rhizoma dioscoreae compound beverage disclosed by the invention, season problems of the pumpkin and rhizoma dioscoreae raw materials are solved and a pre-treatment procedure of the raw materials is reduced.