Radio frequency identification (RFID) technology, also known as electronic tag and RFID, is a communication technology that can identify a specific target and read and write related data through radio signals without establishing mechanical or optical contact between the identification system and the specific target. Commonly used technologies include low frequency (125k~ 134.2K), high frequency (13.56Mhz), ultra-high frequency and microwave. RFID readers are also divided into mobile and fixed. At present, RFID technology is widely used, such as library, access control system, food safety traceability and so on.