An array substrate and a fabrication method thereof, and a display panel are provided. The array substrate includes: a base substrate; a first electrode layer and a first pixel defining layer, on the base substrate; a light emitting layer, on the first electrode layer; and a second pixel defining layer, on the first pixel defining layer and the light emitting layer, wherein, the second pixel defining layer overlaps with the light emitting layer in a direction perpendicular to the base substrate.