A method for fabricating a touch display substrate and a touch display substrate are provided to solve the problem that existing touch electrodes of the micron-scale line width cannot meet the high PPI requirement. The fabrication method includes forming functional layers of an organic light-emitting diode (OLED) device on a base substrate sequentially to obtain an OLED substrate; and forming a linear touch electrode with a nano-scale line width on the OLED substrate by electronic sputtering and transferring.