Abstract: In order to get rid of the noise of fingerprint image effectively and cut down the time of identify so it can be used to the real-time system more appropriate, this paper proposed a fingerprint pre-processing scheme based on 8 directional ridge-direction filter, which based on the thorough study of the fingerprint image pre-processing algorithm which has the highest time complexity in Automatic Fingerprint Identification System(AFIS). This scheme based on direction approximation method while getting the point orientation map of fingerprint, employed the mean filter algorithm which can reduce the influence of fingerprint image noise, not only made the consistency of point orientation map better but also made the performance of results more stable. And then designed a suite of 8 directional ridge-direction filter which corresponding with the direction information of fingerprint image according to the design principles of ridge-direction filter. At last adopted the method of look-up to select ridge-direction filter corresponding with the fingerprint direction information of each pixel, to enhance fingerprint image. Experiments are done on the FVC2004 databases DB1_B with the FVC2004 performance evaluation method and the results show that our scheme is simply, quickly and efficiently that can be widely used in real-time Automatic Fingerprint Identification System(AFIS).