1. An ontology enhancement method, comprising: step A: receiving at least an input information request; step B: based on an ontology, expanding each input information request to produce at least an expanded information request of each corresponding input information request; step C: based on a searching model, according to each expanded information request, searching a file collection to obtain searching results of each corresponding expanded information request; step D: according to each searching result, extracting a plurality of candidate knowledge concepts of each corresponding searching result; and step E: selectively adding the candidate knowledge concepts of each searching result into the ontology.