The digital recognition system is an important part of the modern intelligent management field. Its role is particularly reflected in the intelligence and digital aspects of daily life. With the bank card of China's Banks as the research object, this paper proposed a bank card number automatic identification technology based on digital image processing. The main purpose of this technology is to achieve the automatic extraction of bank card number information as a text file output for practical applications. Its main components are image acquisition, image preprocessing, digital number positioning, character feature extraction, character recognition, character segmentation and character recognition, etc. Through the experimental test, it is found that the technology can achieve more than 85.6% accuracy.