The invention discloses a display panel and a preparation method thereof, and a
display device. The display panel comprises a substrate; an
anode layer which is arranged on the substrate; a pixel defining layer which is arranged on the
anode layer and is provided with an opening, wherein the opening forms a pixel area used for containing pixel ink; an
OLED device layer which is arranged on the
anode layer of the pixel region, wherein the pixel defining layer is in an L-shaped step shape, and the middle thickness of the pixel defining layer is smaller than the edge thickness. According to the display panel, the preparation method thereof and the
display device, the L-shaped stepped pixel defining layer is prepared, and the middle thickness of the L-shaped stepped pixel defining layer is smaller than the edge thickness, so that the film thickness at the edge and the middle of an
OLED device layer formed by ink-jet printing is uniform, and the problems of non-uniform
luminescence or shortservice life and the like are solved.