An active small-molecule donkey-hide gelatin mixture and a preparation method and application thereof. The active small-molecule donkey-hide gelatin mixture is prepared by using the compound protease comprising the proline protease to perform the enzymatic hydrolysis on the donkey-hide gelatin juice to which no auxiliary material is added. For the active small-molecule donkey-hide gelatin mixture, the weight-average molecular weight ranges from 580 Da to 1300 Da, the peptide segments are distributed from 200 Da to 3000 Da, the dissolution rate in cold water is high, and the content of free amino acid is low; the active small-molecule donkey-hide gelatin mixture may be used for manufacturing small-molecule peptide food and health care food of donkey-hide gelatin.