An automatic cash-binding machine register system for paper currency numbers is developed in this paper. The paper currency number is recognized and recorded by the system during binding. It can be used as an assistant method for investigation cases of bank highjack and false paper currency. The hardware of the system is composed of money-binding machine, camera, lamp-house, image gather-card and computer. To improve recognition speed, the area of number image is decreased by adjust the camera’s location on the binder. A size of 200×40 pixel is chosen in the system. The software of the system is made up of number image sample, segmentation of gray ridge-vale algorithm, orientation of projection, recognition of structure-analyzing algorithm and record. Factors as follows: the software run-speed, illumination uniformity the fray and smutch in the paper currency are considered. A random experiment with two hundred sheets of RMB 100 Yuan is given. The recognition ratio is 98%, and the average time for one sheet is about 30ms in the experiment. It can content the speed demand of binder binding money. The system has been applied national patent.