Fingerprint image processing method and device are provided, and the fingerprint image processing method includes following steps. A plurality of first fingerprint features are extracted from a fingerprint image by a first search algorithm. An inverse process is performed on the fingerprint image to obtain an inverse fingerprint image. A plurality of reference features are extracted from the inverse fingerprint image by the first search algorithm. A plurality of second fingerprint features are obtained from the fingerprint image based on coordinates of the reference features.