The invention relates to a mulberry composite fruit and vegetable juice beverage and a preparation method thereof, belonging to a technical field of beverage. Provided is a composite fruit and vegetable juice beverage produced by taking mulberry as a main material. The beverage comprises, by weight, mulberry juice 50%, haw juice 10%, dangshan yellow pear juice 10%, Chinese yam juice 10%, water 9%, food additives 1%, carboxymethylcellulose sodium 0.2%, xanthan gum 0.1%, citric acid 0.2%, aspartame 0.1%, sodium erythorbate 0.2%, and a sodium chloride solution 0.2%. The prepared mulberry composite fruit and vegetable juice beverage has the advantages of delicious taste, bright color, strong aroma and unique local flavor, and the beverage has multiple kinds of nutrition components of resveratrol, hawthorn flavonoid, vitamin and the like. The beverage has efficacies of liver tonifying and strengthening kidney, blood circulation promoting to remove blood stasis, lung moistening to arrest cough, spleen invigorating.