本文设计了一套指纹图像预处理和指纹特征提取算法, 利用方向滤波的方法对原始图像进行增强,使用改进的细化算法进行细化, 最后基于脊线跟踪的方法, 用改进的算法更为简洁而有效地避免了各种伪特征。设计的算法经Matlab 实现, 实验效果良好。-Designed a fingerprint image and fingerprint feature extraction algorithm using directional filtering the original image enhancement, improved thinning algorithm refinement, the last ridge line tracking method, the improved algorithm is more simple and effective way to avoid the pseudo-characteristic. Design algorithm with Matlab, the experiment well.