A touch substrate and a method for forming the same, and a touch display device are provided, relating to the field of display technology. The touch substrate includes a touch region and a light-shielding region surrounding the touch region, a light-shielding pattern is arranged at the light-shielding region; the touch substrate further includes a first touch electrode and a second touch electrode crossing each other and insulated from each other and virtual electrodes at regions defined by the first touch electrode and the second touch electrode, and each virtual electrode is spaced apart from the first touch electrode and the second touch electrode; the first touch electrode, the second touch electrode and the virtual electrodes contact the light-shielding pattern; portions of adjacent virtual electrodes at the light-shielding region are connected to each other via a first bridge, the first bridge is insulated from the first touch electrode and the second touch electrode; and a first ground wire is arranged at the light-shielding region, and the first ground wire is electrically connected to the virtual electrodes connected to each other via the first bridge.