A complete combinatorial pre-processing algorithm based on the characteristic of capacitance sensor fingerprint image was pointed out. The problems were considered in this algorithm such as fingerprint image’s quality and area and so on, and the filter was increased twice based on the original algorithm to enhance fingerprint ridge and eliminate noises effectively for better preprocessing result. Firstly, the fingerprint image was filtered by edge keep filter. Then, the image was enhanced by the algorithm based on the lines of directional of Gabor filter, which could reduce the effect of the rotation and shift of the images on the fingerprint recognition. Finally, the thinning image was received in the morphological thinning method after dynamic threshold method and the second filter were used to receive a binary image. The experimental result proves that this algorithm is effective to fingerprint image and helpful to the fingerprint feature extraction and matching.