The invention belongs to the field of food processing, and relates to a peanut dietary fiber ultrasonic wave or microwave auxiliary extraction and purification method which comprises the following steps of: carrying out ultrasonic wave or microwave auxiliary extraction on the prepared peanut powder, and obtaining water-soluble dietary fiber by protein precipitation, membrane filtration concentration, column chromatography, absolute ethyl alcohol precipitation, centrifugation and drying; and after ultrasonic wave or microwave treatment, carrying out complex enzyme hydrolysis and decoloring refining on the peanut powder, and obtaining insoluble dietary fiber. The prepared water-soluble dietary fiber product has 50-90% of non-starch polysaccharide, and the insoluble dietary fiber product hasthe purity of 80-95%, so that the peanut dietary fiber has the physiological functions of preventing coronary heart disease, controlling and treating obesity, adjusting blood sugar, treating diabetesmellitus, regulating blood fat, preventing hypertension, adjusting the functions of intestines and stomach, preventing cancers, removing exogenous noxious substances and the like, and can be taken asfunctional food material or health food. The method can be used for obtaining the peanut dietary fiber with high content, purity and activity, and is suitable for industrialized production.