a method for producing clear , concentrated sweet potato juice , including : a ) cleaning , peeling , crushing , and gelatinizing a raw material of sweet potatoes to yield a sweet potato paste , and squeezing the sweet potato paste to obtain skin dregs and a squeezed clear juice ; b ) performing enzymolysis to part of the skin dregs and adding the hydrolyzed skin dregs to the sweet potato paste for squeezing ; c ) performing enzymolysis and filtering to the squeezed clear juice to obtain a sweet potato clear juice ; d ) combining the rest part of the skin dregs and sweet potato skins generated during the peeling process to obtain a sweet potato residue ; e ) extracting dietary fiber from the sweet potato residue ; and f ) adding the dietary fiber to the sweet potato clear juice and post - treating the sweet potato clear juice .