Goal Aiming at the problem that the image of motor vehicle registration certificate is printed incorrectly and the characters are crossed by lines, a set of character recognition algorithm is designed based on Halcon machine vision software. Method Firstly, the image is tilt corrected、enhanced、binarized; Extraction of table lines by specific structure corrosion method, the original image area is divided into two parts: table and character; Based on the vertical projection segmentation method and the character spacing merging algorithm, a single character is segmented, in which the characters crossed by the table line will have obvious fracture. The region detection and filling algorithm specifies the structural elements and parameters to detect and fill the internal and edge fractures of the region to realize fracture splicing. Finally, the spliced characters are trained and recognized based on multi-layer perceptron, and the results are typeset and displayed in the table. Result Experimental results show that the algorithm can preprocess the registration certificate image and recognize characters, and the recognition accuracy is 97.28%. Conclusion Through the above algorithm, the efficiency of extracting information from complex background can be greatly improved.