A touch display substrate includes: a base substrate, a common electrode layer on the base substrate, a plurality of touch data lines, and a touch detection chip. The touch detection chip is connected with each of the self-capacitive electrodes through a corresponding one of the touch data lines and configured to load a common electrode signal to each of the self-capacitive electrodes in a display period through the corresponding touch data line. The touch detection chip is also configured to determine a touch position in a touch period by detecting a change in a capacitance of each of the self-capacitive electrodes through the corresponding touch data line.