Terminal protection structure for high-voltage power device and preparation method thereof

The invention provides a terminal protection structure and a preparation method thereof, and a high-voltage power device. The terminal protection structure comprises a substrate of a first conductive type, an insulating layer, a metal field plate and a protection layer, more than two heavily-doped second conduction type terminal rings which are arranged at intervals are formed in the substrate, the insulating layer is located on the surface of the substrate, one ends of the metal field plates penetrate through the insulating layer until the metal field plates are connected with the two terminal rings located on the outermost side in a one-to-one correspondence mode, the other ends of the metal field plates oppositely extend to the position above the insulating layer, and the metal field plates are mutually insulated; the protective layer is located on the insulating layer and the metal field plate. According to the preparation method of the terminal protection structure for the high-voltage power device provi