The invention discloses a touch display panel, and a driving method and a display device thereof, relates to the technical field of display, and does not increase the thickness of the display panel when the display panel is caused to have a touch function. The touch display panel comprises an upper substrate and a lower substrate, wherein the upper substrate and the lower substrate are oppositely arranged, the lower substrate is provided with a plurality of grid lines and a plurality of data lines, a plurality of sub-pixel areas are defined by the plurality of grid lines and the plurality of data lines, each sub-pixel area is provided with a common electrode block, and at least one common electrode block is reused as a self-capacitance electrode; the touch display panel also comprises a touch detection chip, and each self-capacitance electrode is connected with one output end of the touch detection chip through at least one conductor; and the touch detection chip is used for loading a touch detection signal on the self-capacitance electrodes within a touch time period and judging a touch position through the detection of the capacitance value change of each self-capacitance electrode, and the above touch display panel is used for causing the display device to have a touch function.