The invention discloses a light emitting diode epitaxial wafer and a manufacturing method thereof, belonging to the field of semiconductor technology. The epitaxial wafer comprises a substrate and a buffer layer sequentially laminated on the substrate, an N-type semiconductor layer, an active layer and a P-type semiconductor layer, wherein the active layer comprises a plurality of composite structures laminated in sequence, each of the composite structures comprises a well layer, a cap layer and a barrier layer laminated in sequence, the material of the well layer is InGaN, the material of thebarrier layer is GaN, and the material of the cap layer is BxGa1-xN, 0