A method for driving touch display and a touch display screen are provided. The touch display screen includes a plurality of continuous work time periods. Each work time period includes a display time period and a touch time period. In the display time period, a plurality of second signal lines are configured to cooperate with a plurality of third signal lines to perform image-signal transmission for image display. The touch time period includes a detection time period and a sensing time period. In the detection time period, at least one second signal line of the plurality of the second signal lines is provided with a touch driving signal, a detection signal is received from a plurality of first signal lines, the detection signal is compared with a preset signal to obtain a comparison result, the touch time period is prolonged or shortened according to the comparison result.