The invention discloses a light-emitting diode epitaxial wafer and a manufacturing method thereof, belonging to the technical field of semiconductors. The epitaxial wafer includes a sapphire substrate, and an undoped GaN layer, an N-type GaN layer, an active layer, and a P-type GaN layer sequentially stacked on the sapphire substrate, and the active layer is an alternately grown InGaN layer and a GaN layer , the epitaxial wafer also includes a superlattice GaN layer, the superlattice GaN layer is laminated between the undoped GaN layer and the N-type GaN layer, and the superlattice GaN layer includes alternately grown first GaN layers and second GaN layers, The first GaN layer is grown in a three-dimensional 3D mode, and the second GaN layer is grown in a two-dimensional 2D mode. By inserting a GaN layer grown in a 3D mode, the present invention can deflect and merge dislocations on the one hand, and on the other hand, effectively change the direction of light reflected back by total reflection, so as to re-emit, thereby improving the luminous efficiency of the LED.