Abstract:Sweet potato residue has abundant soluble dietary fiber （SDF），which is not fully utilized. SDF has water binding capacity，moisturizing，and stability，which can be used as a food additive. It can improve intestinal function，regulate blood sugar and lipids，and enhance immunity，serving as an ideal functional food resource. In this paper，the composition，structure，and properties of SDF from sweet potatoes were analyzed，and then its extraction and separation methods were summarized. Finally，its physiological activity function was discussed，so as to provide a reference for the development and resource utilization of SDF from sweet potatoes.