The present disclosure provides a touch display panel and its controlling method. The touch display panel includes a plurality of first touch electrodes and a plurality of first touch electrode lines arranged on an array substrate, a plurality of second touch electrodes and a plurality of second touch electrode lines arranged on a color filter substrate, and region scanning electrodes. Each first touch electrode line is connected to each first touch electrode, and each second touch electrode line is connected to each second touch electrode. All the first touch electrodes are located at one half of a display region of the touch display panel, and all the second touch electrodes are located at the other half of the display region of the display panel.