The invention discloses yam bean 
dietary fiber powder with a 
prebiotic function and a preparation method thereof.The yam bean 
powder is prepared by taking fresh yam bean tuberous roots as raw materials through the steps of cleaning, peeling, 
slicing, color protecting, first-time 
grinding, freezing 
grinding, limited enzymolysis performing and 
drum drying, crosslinking adsorbing, complexing, secondary 
grinding, mixing, 
extrusion granulating, sieving and packaging, the prepared yam bean 
powder retains all dietary fibers of the yam beans and the original 
flavor of the yam beans, contains high-resistance 
starch and has the instant 
solubility and the 
prebiotic function.According to the yam bean 
dietary fiber powder with the 
prebiotic function and the preparation method thereof, embedding crosslinking, complexing, enzymatic debranching treating and 
drum drying are combined to be applied to the production process of the yam bean 
dietary fiber powder, the dissolving ability of the yam bean powder can be effectively improved, the fluidity and 
solubility are improved, the content of the resistance 
starch in the product is increased, and the significant effects on regulating the intestinal microecological balance and improving the 
gastrointestinal function are achieved; in addition, powder granules produced through 
extrusion granulating are uniform in granule size, loosened and porous and can be swelled and gelatinized in a short time, and therefore the good instant 
solubility and wet permeability are achieved.