1. A facial image search system, comprising: a storage module configured to store a plurality of facial features as a database in advance; an image receiving module configured to receive image data; a face detection module configured to detect a facial image from the image data received by the image receiving module; a feature extraction module configured to extract the facial features from the facial image detected by the face detection module; a search module configured to calculate a degree of similarity between the facial features extracted by the feature extraction module and the facial features contained in the database and output a search result based on the calculated degree of similarity; a measuring module configured to measure an amount of the search result output by the search module; a selection module configured to sort out the search result output by the search module if the amount of the search result measured by the measuring module is equal to or more than a preset threshold; a display control module configured to generate a search result screen based on the search result sorted by the selection module; and an output module configured to output the search result screen generated by the display control module.