QR code, also known as QR code, is a popular encoding method on mobile devices in recent years. It can store more information and represent more data types than traditional Bar Code barcodes A two-dimensional bar code is a graphic that records data symbol information in black and white, distributed in a plane (two-dimensional direction) according to a certain pattern using a specific geometric shape; Cleverly utilizing the concept of "0" and "1" bit streams that form the internal logic foundation of computers in code development, using several geometric shapes corresponding to binary to represent textual numerical information, and automatically recognizing and processing information through image input devices or photoelectric scanning devices: it has some commonalities of barcode technology: each code system has its own specific character set; Each character occupies a certain width; Has certain verification functions, etc. At the same time, it also has the function of automatically recognizing information from different peers and processing changes in graphic rotation