Display panel, preparation method thereof and display device

The embodiment of the invention provides a display panel, a preparation method thereof and a display device, and belongs to the technical field of display. The display panel comprises a substrate and a light-emitting layer arranged on one side of the substrate; the at least three packaging layers are arranged on one side, deviating from the substrate, of the light-emitting layer; wherein the refractive indexes of all the packaging layers included in the at least three packaging layers are different, and the sizes of all the packaging layers in the first direction are different; the refractive index of each packaging layer in the at least three packaging layers is greater than or equal to 1.4 and less than or equal to 2.6; the size of each packaging layer in the at least three packaging layers in the first direction is larger than or equal to 100 nm and smaller than or equal to 600 nm. According to the display panel, the preparation method thereof and the display device provided by the embodiment of the invent