Only one deposit-free social security card reader card can be applied for each social security card. The ID number is the reader card number, and the initial password is 6 digits after the ID number. Readers who have successfully opened the social security card reader card can borrow 10 books in the main library, and the total price of books does not exceed that of 400 yuan. Social security card readers can borrow and return books at the manual service desk of the main branch library with their ID cards, or bind the official WeChat account of Dongguan Library (branch library) and use the QR code electronic identity to borrow and return books on the self-service equipment that supports QR codes.