A touch display device with a force sensing function is provided. The touch display device includes a touch display panel, a backlight circuit and a force sensor. The backlight circuit is disposed on a back surface of the touch display panel. The force sensor includes a first conductive layer, a second conductive layer, an insulation layer and a third conductive layer. The first conductive layer is disposed between the touch display panel and the backlight circuit, the second conductive layer is disposed between the first conductive layer and the backlight circuit, and the insulation layer is disposed between the first conductive layer and the second conductive layer. The backlight circuit is disposed between the second conductive layer and the third conductive layer. The first conductive layer, the second conductive layer and the third conductive layer are electrically insulated from one another.