Abstract: Natural plant-derived dietary fiber (DF) is rich and has important physiological functions for human health. As the main active component of DF, the content of SDF is related to the quality of DF. Due to the low content of SDF and poor physical properties of natural plant DF, DF can not be fully utilized, which restricts the development and application of DF-related functional products. Therefore, it is urgent to use processing technology to treat DF to increase the content of SDF and improve the physicochemical and structural characteristics of DF. Ultrasonic technology, as an efficient and environmentally friendly modern food processing method, can change the structure of the material, improve yield of DF in raw material, and promote the dissolution of active ingredients by cavitation and mechanical effects. The ultrasonic technology is an effective method to improve the processing and functional characteristics of products, which is widely used in the preparation and modification of DF. This paper mainly reviews the improvement of SDF content in DF by ultrasonic technology, and focuses on the effect of ultrasonic technology on the structural characteristics, hydration characteristics, adsorption characteristics and viscosity of DF. Finally, the problems existing in the existing research are analyzed and summarized, and the future research trends are prospected to provide theoretical basis for the in-depth development and application of DF.