Abstract: An aspect of the present disclosure provides a method of recognizing and classifying design information by automatically digitizing an imaged P&ID drawing to digitize design information by totaling design elements with high accuracy within a short time, and another aspect of the present disclosure is to obtain an imaged P&ID drawing or a database stored in a text form as a digitized drawing by modeling a symbol, line, and text in an intelligent P&ID, thereby accurately and rapidly quoting a price and accurately checking compatibility between different design products.