The present invention discloses a touch display panel, a detecting method thereof, and a display device. The common electrode layer is divided into a plurality of independent self capacitance electrodes, and the common electrode is multiplexed as self capacitance electrodes. There is no need to provide an additional film, and it is only required to modify the pattern of the common electrode layer in the current LCD panel. Thus, the production cost is reduced, and the production efficiency is improved. Since the self capacitance electrodes are formed by dividing the common electrode layer in the above-mentioned touch display panel, a compensating electrode is further provided which is arranged in a layer different from that of the self capacitance electrodes, is insulated from the self capacitance electrodes, and at least covers a portion of a partition gap between neighboring self capacitance electrodes. A common electrode signal is applied to the compensating electrode during a display period. In this way, the common electrode signal which is applied to the compensating electrode during display can compensate the common electrode signal at partition gaps of the self capacitance, thus ensuring that liquid crystal molecules at partition gaps normally invert and that the overall display panel displays normally.