The invention discloses a mobile payment device and a method thereof based on an NFC technology, and the NFC technology and hardware encryption are combined. According to the mobile payment device and the method thereof, the NFC technology and the hardware encryption are combined and applied to the field of mobile terminal payment for the first time, and compared with traditional software encryption like dynamic passwords, the hardware encryption is higher in safety and reliability. The mobile payment device is designed in a folding type, a display screen can be folded and put into an outer shell of the mobile payment device when not used, therefore, the occupied space is small, the display screen is protected effectively, and damage to the display screen in the process of mobile carrying can be prevented. The payment device is small in size, easy to carry, and capable of being integrated into a card with a liquid crystal display. According to the mobile payment device and the method thereof, a hardware encryption mode is adopted, a secret key is stored in hardware, safety of the secret key can be guaranteed on the hardware, the secret key in the payment device can not be obtained by the outside through a mobile terminal, possibilities of exposure of the secret key are reduced, and therefore payment can be safer.