The present disclosure relates to an LED epitaxial structure and a manufacturing method therefor, a light emitting device and a display panel. The LED epitaxial structure includes: a substrate, an N-type confinement layer, an active layer and a P-type confinement layer, which are disposed in sequence from bottom to top, wherein the active layer includes quantum well layers and quantum barrier layers, which are alternately disposed, a part of the quantum barrier layers are first quantum barrier layers, at least one of the quantum barrier layers is a second quantum barrier layer, the second quantum barrier layer is located between two first quantum barrier layers, and a thickness of the second quantum barrier layers is greater than a thickness of the first quantum barrier layers.