Provided are a light-emitting diode and a semiconductor device. The light-emitting diode comprises: a substrate; and a buffer layer, an N-type gallium nitride layer, a light-emitting region buffer layer, a first light-emitting layer, a second light-emitting layer, an electron blocking layer, and a P-type gallium nitride layer that are epitaxially grown on the substrate sequentially, wherein: the second light-emitting layer comprises one or more light-emitting well-barrier pair sub-layers; the thickness of the light-emitting region buffer layer is a preset first multiple of the thickness of the light-emitting well-barrier pair sub-layer; the thickness of the first light-emitting layer is a preset second multiple of the thickness of the light-emitting well-barrier pair sub-layer, the second multiple being less than the first multiple; and the thickness of the electron blocking layer is a preset third multiple of the thickness of the light-emitting well-barrier sub-layer, the third multiple being less than the first multiple.