The invention discloses a preparation method for an enzyme-modified peanut protein, which includes the following steps: low-denatured degreased peanut protein powder suspension is added into distilled water, and microwave-assisted dispersion and dissolution is carried out; the pH value is regulated, and microwave-assisted alkali extraction is carried out; after centrifugation, supernate is ultrafiltered, the pH value of concentrate is regulated, protease is added, and microwave-assisted enzymolysis is carried out; after enzyme inactivation, ultrafiltration, separation and concentration, concentrate is frozen and dried, and thereby the enzyme-modified peanut protein is obtained. The enzyme-modified peanut protein product prepared by the preparation method has good dissolvability, foamability and foam stability, and can be used for improving the processability of food. The preparation method has the advantages of mild enzyme modification conditions, short reaction time and low cost, andis suitable for industrialized production.