The disclosure discloses a display panel and a preparation method thereof, and a display device. The display panel includes a base substrate on which a plurality of repetitive units are arranged; each repetitive unit includes a display area, a transparent area and a metal wiring area; a ¼λ phase difference layer and a polarization layer arranged on the packaging layer and stacked in sequence, where the polarization layer is positioned on the side, far away from the packaging layer, of the ¼λ phase difference layer; the ¼λ phase difference layer and the polarization layer have openings in the direction perpendicular to the base substrate, and orthographic projections of the openings on the base substrate are positioned in the transparent area; and orthographic projections of the ¼λ phase difference layer and the polarization layer on the base substrate cover the display area.