An optical touch substrate, an in-cell touch panel and a display device are disclosed. The optical touch substrate includes a base substrate, a light shielding matrix and a plurality of pixel regions defined by the light shielding matrix. The light shielding matrix includes a plurality of first optical touch electrodes and a plurality of second optical touch electrodes arranged to cross each other. The first optical touch electrodes are insulated from the second optical touch electrodes, and at least one optical touch electrode of the plurality of first optical touch electrodes and the plurality of second optical touch electrodes includes a photosensitive layer and a conductive layer provided in a stacked manner. A sensing signal on each optical touch electrode changes as an intensity of light irradiated to a corresponding photosensitive layer changes.