The present disclosure discloses a method and apparatus for acquiring information. The method comprises: acquiring images of a plurality of unregistered users, the unregistered users being users having no registered images belonging to the unregistered users in a face recognition system; calculating a maximum similarity corresponding to an image of each unregistered user, the maximum similarity being a maximum similarity among similarities between a face object in the image of the unregistered user and face objects in a plurality of registered images; and determining a similarity threshold corresponding to a preset condition based on the calculated maximum similarity corresponding to the image of the each unregistered user, the preset condition comprising a ratio of a number of images of the unregistered users with corresponding maximum similarities greater than the similarity threshold to a number of the images of the unregistered users being smaller than a ratio threshold.