The invention discloses a pedestrian re-identification method. The method comprises steps of pedestrian characteristic extraction and pedestrian characteristic tolerance, for pedestrian characteristic extraction, image color histograms are extracted through employing sliding windows, main colors are expanded, statistics of appearance frequency of each color mode is carried out at each sliding window, sum of relatively larger frequencies is taken as characteristic output of the color, traversal of an integral image is carried out through the sliding windows, and characteristics are formed after normalization; for more generalization matching, a search source is extracted from characteristics of a full body to a half body; for tolerance calculation, characteristic dimensions with a non-zero search image characteristic vector and to-be-searched-target characteristics are taken as an Euclidean distance, and interference of background factors under a complex scene is further reduced. The method is advantaged in that re-identification under the complex scene is carried out, properties of strong transportability for scene change, stable algorithm and fast speed are realized, a problem of poor quality of monitoring videos and to-be-searched databases can be effectively solved, and strong practicality is realized.