Tethered UAV, also known as tethered UAV, is a special form of multi-rotor UAV. It uses ground power transmitted through tethered cables as a power source instead of traditional lithium batteries. It is characterized by the ability to hover in the air for a long time. The tethered drone is composed of a ground high-voltage DC voltage stabilization system, a pay-off device, a synchronous reel, a mooring cable, an air voltage stabilization module and a backup battery. The high-voltage DC voltage stabilization system And the synchronous reel is installed on the reel, and the tethered cable is connected with the voltage regulator module and the backup battery.