A touch display device includes a touch screen, a plurality of physical keys surrounding the touch screen, a touch sensor, and a touch control system. The touch screen senses a touch operation and displays a graphical user interface (GUI). The physical keys are arranged on each side of the touch screen, and the touch keys on one side can be enabled while the physical keys on all other sides are disabled. The touch sensor includes a plurality of touch sensing units which outputs a touch signal when one side is touched. The touch control system rotates the GUI through predetermined numbers of degrees to maintain uprightness for the user, enables the touch keys on the touched side, and disables the touch keys on all the other sides according to the touch signal.