How many volts is the high voltage?

Above 1000 volts
High voltage electricity usually refers to electrical wires with a voltage above 1000 volts, while in the power system, voltages above 1 kilovolt (kV) are usually defined as high voltage.
Specifically, the range of high voltage can be extended to 220 kV, and beyond this range, such as 330 kV to 750 kV, are classified as ultra-high voltage, while AC voltage above 1000 kV or DC voltage above 800 kV is defined as ultra-high voltage.