1. A computer-implemented method for estimating an orientation field of a fingerprint, comprising: receiving a fingerprint to be estimated, obtaining an initial orientation field of the fingerprint to be estimated, and putting the initial orientation field in a reference coordinate system; obtaining N initial orientation blocks corresponding to the initial orientation field, in which the N initial orientation blocks correspond to N positions of the initial orientation field in the reference coordinate system respectively, and obtaining N orientation block sets corresponding to the N positions respectively from a fingerprint dictionary, in which the fingerprint dictionary comprises M orientation block sets corresponding to M positions in the reference coordinate system, and each of the M orientation block sets comprises a plurality of orientation blocks corresponding to a plurality of training fingerprints in one position of the M positions respectively and in which N≦M; obtaining a similarity between each of the N initial orientation blocks and each orientation block in the N orientation block sets corresponding to the N positions to obtain P similarities, and selecting a preset number of candidate orientation blocks for each of the N positions from the orientation block set according to the P similarities; obtaining a compatibility between two candidate orientation blocks corresponding to any two adjacent positions of the N positions respectively to obtain a plurality of compatibilities; and obtaining a candidate orientation block for each position from the preset number of candidate orientation blocks according to the P similarities and the plurality of compatibilities, and generating an orientation field of the fingerprint to be estimated according to the candidate orientation block for each position.