Abstract: A smart card is disclosed by the present invention. The smart card comprises a flexible keyboard, an ultra thin flexible battery, an infrared data interface, a flexible display, a flexible circuit board and a CPU kernel; wherein the flexible circuit board provides electrical connection for individual parts of the smart card, the flexible keyboard is used for inputting by user, the ultra thin flexible battery provides power supply to the smart card, the infrared data interface is used for infrared communication with an external terminal, the flexible display is used for man-machine interaction, the CPU kernel controls individual parts of the smart card and the smart card is packaged with plastic material. The invention enables the smart card to authenticate off-line user, therefore the security of electronic transaction is ensured. The smart card product of the invention can be carried and used by user conveniently, and can reduce product costs and has very wide application prospect.