There is provided a touch display device including a display and a touch control device. The display includes a glass substrate. The touch control device is attached to the glass substrate and includes a touch zone, a fingerprint detection zone and a control circuit. The touch zone includes a matrix of first detecting cells arranged at a first grid distance. The fingerprint detection zone includes a matrix of second detecting cells arranged at a second grid distance. The control circuit is configured to control detection operations of the touch zone and the fingerprint detection zone and to adjust an effective grid distance of the fingerprint detection zone according to a first detected touch position.