A flash memory device with a plurality of protocols comprises a body, a memory device, a terminal group, and a control unit. The control unit is connected to the memory device and the terminal group for driving and controlling data access in the memory device. The control unit is at least able to transfer data by a SD (Secure Digital) protocol and a MMC (MultiMedia Card) protocol. The control unit further comprises a detection circuit. The detection circuit can detect the protocol supported by an external device, and can switch the control unit to use the SD protocol or the MMC protocol to transfer data to the external device.