Provided are an organic electroluminescent display panel, a preparation method thereof, and a display device. In the organic electroluminescent display panel provided in the present disclosure, an etching layer comprising at least a convex with a narrow upper portion and a wide upper portion is disposed between a base substrate and a plurality of display components, wherein a top surface of the convex is in an display area of the base substrate, a display component on an edge of the display area of the base substrate extends beyond the convex, and an inorganic film of a thin film encapsulation structure is broken at a tip of the display component extending beyond the convex.