The invention relates to a three-
electrode discharge device for generating a large-volume
atmosphere pressure
plasma. The device comprises a coaxial medium tube, a grounding flat
hydropower pole, a
tungsten needle electrode and a
low temperature plasma generator power source, wherein the coaxial medium tube is a double-layer tubular sealed container having an axial center inner-cavity and a U-shaped section, and the side wall of the sealed container is provided with an air inlet used for filling working air; the
tungsten needle electrode is inserted from the seal end of the coaxial medium tube into a center inner-cavity of the coaxial medium tube, the front end of the
tungsten needle electrode is positioned at the open end of the center inner-cavity of the coaxial medium tube, and the back end of the tungsten needle
electrode is connected with an output
electrode of the
low temperature plasma generator power source; and the grounding flat
hydropower pole is positioned on the outer side of the open end of the coaxial medium tube, and is electrically connected with a grounding electrode of the
low temperature plasma generator power source. The device can be used in the technical fields of
plasma lamp and
plasma display manufacturing, plasma film generation,
plasma surface modification and the like, and can be used for generation of
ozone, treatment for waste water and
exhaust gas, sterilization and disinfection, plasma stealth and the like.