A center-extracted algorithm by combining the Kalman filter with the Hessian matrix was proposed for the implementation of real-time stripe processing in rail wear dynamic measurement. Firstly, the image region of a laser stripe in rail wear dynamic measurement was predicted with the Kalman filter method. Then,the points with max gray were searched in the predicted region of laser stripe line by line, and they were considered as the initial positions of laser stripe image center. Sub-pixel positions of laser stripe image center were then extracted through the calculation of Hessian matrix in the initial positions of laser stripe image center. Finally, the sub-pixel image center of laser stripe was obtained in the region of stripe. The proposed algorithm reduces the searching area and the number of Gaussian convolutions greatly, and improves the robustness and speed in the extraction of laser stripe centre in the rail wear dynamic measurement. Experimental results show that it takes 1.6 ms to process every frame, and the extraction accuracy of laser stripe is also guaranteed.