The invention discloses a preparation method of highland barley dietary fiber-polyphenol compounds. The preparation method specifically comprises the following steps: dissolving highland barley flour in a buffer solution to obtain a mixture I, performing enzymolysis on the mixture I in a dark place, centrifuging while the enzymatic hydrolysate is hot to obtain precipitates which are highland barley insoluble dietary fiber-polyphenol compounds (IDF-PC), collecting and freezing the precipitates at low temperature, performing vacuum freeze drying on the frozen precipitates, and storing the vacuum freeze-dried precipitates at -20 DEG C; adding alcohol into centrifuged liquid supernatant to obtain a mixture II, standing and naturally cooling the mixture II to the room temperature, precipitating and staying the mixture II overnight at low temperature, taking a lower-layer muddy part and centrifuging to obtain precipitates which are highland barley soluble dietary fiber-polyphenol compounds (SDF-PC), collecting and freezing precipitates at low temperature, performing vacuum freeze drying on the frozen precipitates, and storing the vacuum freeze-dried precipitates at -20 DEG C. According to the preparation method of the highland barley dietary fiber-polyphenol compounds disclosed by the invention, the highland barley soluble dietary fiber-polyphenol compounds and the highland barley insoluble dietary fiber-polyphenol compounds are separated and prepared by utilizing an enzyme weight method, so that scientific basis is provided for developing and utilizing the highland barleys and a new thought is also provided for deeply processing the highland barleys, and therefore, the development of the highland barely industry is promoted.