a valid method of fingerprint Image pre-processing is introduced． Experiment resultsshow that this kind of algorithm can availably wipe off yawp imported by the incomplete leavefingerprint-marking of sensor surface when fingerprint sensor record fingerprint． Meanwhile， it can extract theeffective and uneffective zone of fingerprint effectively, and also further enhance ridge line and vale line offingerprint so that make the lines of fingerprint clear，continuum，lubricity and has better contrast， at the sametime， has quite quick speed， this fingerprint Image pre-processing time can be shorten greatly．