A display panel, a manufacturing method thereof and a display device are provided. The display panel includes a plurality of functional layers arranged on a base substrate. A portion of at least one of the functional layers is removed to form a gap portion. The display panel further includes a light-transmissible structure including the gap portion and configured to allow a light beam to pass therethrough to an optical sensing element arranged at a position corresponding to the light-transmissible structure. An orthogonal projection of the gap portion onto the base substrate overlaps an orthogonal projection of the optical sensing element onto the base substrate.