The disclosure relates to a high-voltage light-emitting diode (HV LED) and a manufacturing method thereof. A plurality of LED dies connected in series, in parallel, or in series and parallel are formed on a substrate. A side surface of the first semiconductor layer of part of the LED dies is aligned with a side surface of the substrate, such that no space for exposing the substrate is reserved between the LED dies and the edges of the substrate, the ratio of the substrate being covered by the LED dies is increased, that is, light-emitting area per unit area is increased, and the efficiency of light extraction of HV LED is improved.