In the present study, intact potato cells as whole potato food model were isolated through soaking with mild acid and alkali solutions, followed by controlled hydrothermal treatment to reach 0–100% degree of gelatinization (DG). The morphological and structural changes of entrapped starch granules as well as in vitro starch digestion properties were investigated. Our results indicated that the changes of cell wall permeability induced by varied DG values dominated the in vitro starch digestion profiles of intact cells. The gelatinization of intracellular potato starch leads to cell wall expansion and high cell wall permeability, resulting in the accessibility changes of digestive enzymes to encapsulated starch substrates through cell wall barrier. This study suggests that starch digestibility of potato foods can be regulated through cell wall permeability induced by intracellular starch gelatinization degree.