A terminal device (100, 200), wherein the terminal device comprises: a card socket (110, 210), a SIM module (130, 230), a memory card module (120, 220), and a switch, wherein the card socket (110, 210) is configured for placing a SIM card or a memory card; the switch comprises a first switch, a second switch and a third switch; the SIM module (130, 230) comprises at least a SIM data interface, a SIM reset interface, and a SIM clock interface; the memory card module (120, 220) comprises at least a memory card first data interface, a memory card second data interface, and a memory card clock interface; in response to a SIM card placed on the card socket (110, 210), a data interface of the SIM card electrically connected to the SIM data interface via the first switch, a reset interface of the SIM card electrically connected to the SIM reset interface via the second switch, a clock interface of the SIM card electrically connected to the SIM reset interface via the second switch, wherein in response to a memory card placed on the card socket (110, 210), a first data interface of the memory card electrically connected to the memory card first data interface via the first switch, a second data interface of the memory card electrically connected to the memory card second data interface via the second switch, a third data interface of the memory card electrically connected to the memory card third data interface via the third switch, characterized in that the terminal device further comprises a power source, wherein when there is a card placed in the card socket, a voltage of the power source is set to a first voltage; and when the detection circuit detects that the card is the memory card or the SIM card, the voltage of the power source is set to a voltage corresponding to the memory card or the SIM card. a card socket (110, 210), a SIM module (130, 230), a memory card module (120, 220), and a switch, wherein the card socket (110, 210) is configured for placing a SIM card or a memory card; the switch comprises a first switch, a second switch and a third switch; the SIM module (130, 230) comprises at least a SIM data interface, a SIM reset interface, and a SIM clock interface; the memory card module (120, 220) comprises at least a memory card first data interface, a memory card second data interface, and a memory card clock interface; in response to a SIM card placed on the card socket (110, 210), a data interface of the SIM card electrically connected to the SIM data interface via the first switch, a reset interface of the SIM card electrically connected to the SIM reset interface via the second switch, a clock interface of the SIM card electrically connected to the SIM reset interface via the second switch, wherein in response to a memory card placed on the card socket (110, 210), a first data interface of the memory card electrically connected to the memory card first data interface via the first switch, a second data interface of the memory card electrically connected to the memory card second data interface via the second switch, a third data interface of the memory card electrically connected to the memory card third data interface via the third switch, characterized in that the terminal device further comprises a power source, wherein when there is a card placed in the card socket, a voltage of the power source is set to a first voltage; and when the detection circuit detects that the card is the memory card or the SIM card, the voltage of the power source is set to a voltage corresponding to the memory card or the SIM card.