A touch screen display device is provided. The touch screen display device includes a touch screen, a sensor, a control element and a sensitivity-setting element. The sensor is configured to detect if the touch screen display device is being inserted in a connection chamber. The control element is electrically connected with the sensor and is configured to generate a control signal according to an insertion status of the touch screen display device. The sensitivity-setting element is configured to set the touch screen to a first sensitivity or a second sensitivity according to the control signal. The touch screen with the first sensitivity is more sensitive than with the second sensitivity. A method for setting sensitivity of a touch screen is also provided.