The invention provides a multi-card-in-one system and an implementation method. The system comprises an intelligent controller, a read-write module, a security integrated chip, a coil radio frequencymodule, a display module and a main circuit board. The security integrated chip comprises at least two chips, information corresponding to a plurality of financial cards, non-financial cards and certificates is stored in the chips, and the chips are connected with the coil radio frequency module. The display module displays the information and receives an operation instruction. The intelligent controller manages the information according to the operation instruction. The read-write module performs read-write operation on the financial card, the non-financial card and the certificate accordingto the operation instruction. The main circuit board is connected with the intelligent controller, the read-write module, the security integrated chip, the coil radio frequency module and the displaymodule and used for data transmission. The multi-card function is achieved through single-medium integration, all cards protected by the system can be switched for use, the problem that one person holds multiple cards inconveniently is solved, risks are prevented, and resources are saved.