A touch device and a control method thereof are provided. In the control method, a sensing signal generated by a sensor is received. When an operating object is present, a touch screen is configured for touchable regions and untouchable regions, wherein the untouchable regions cannot generate a response through a touch by the operating object. A gesture is received on the untouchable regions of the touch screen, a processor determines whether the gesture is conformed to a default gesture setting, and the processor decides whether or not to adjust part or all of the untouchable regions to the touchable regions according to the determining result. Accordingly, the touch device and the control method thereof of the embodiments of the invention can prevent or lower the occurrence of an accidental touch by a user and enhance the operating convenience of the user.