1. A fingerprint feature identification method, comprising: establishing a plurality of feature triangles according to a plurality of feature points on a fingerprint; respectively calculating a plurality of geometric data on each of the feature triangles; according to a relative direction between any two feature points among the geometric data on each of the feature triangles, alternatively classifying each of the feature triangles into one of each of at least one pair of triangle classifications, wherein two triangle classifications in the same pair of triangle classifications are the same item and opposite results; and storing the feature points, the feature triangles and the geometric data of each of the feature triangles and the corresponding triangle classification of each of the feature triangles in a database for fingerprint identification by doing with the same triangle classification.