The invention discloses a plasma discharging device, relating to a discharging device. The plasma discharging device is provided with an alternating current power supply, a water channel, a plasma generator, an alternating current power supply adjusting circuit, a ground electrode coupling circuit and a gas source, wherein water is injected into the water channel, and the plasma generator immersed in water in the water channel is provided with a chamber, a high voltage electrode and a ground electrode; sealing plates on both sides and a fixed bracket are arranged in the chamber, and the sealing plates on both sides are respectively provided with the high voltage electrode and the ground electrode; both ends of the alternating current power supply adjusting circuit are respectively connected with the high voltage electrode and the positive electrode of the alternating power supply; the ground electrode is connected with a ground electrode coupling circuit, the high voltage electrode is arranged in a sealed pipe and is guided out from the sealed pipe, the fixed bracket is arranged between the sealing plates on both sides, an air inlet is formed below the plasma generator, an air outlet is formed above the plasma generator, and the air inlet is connected with a gas source. The plasma discharging device is less in energy consumption, free from pollution, high in sterilizing efficiency, simple in structure, easy to operate and easy to be popularized in the medical field and industry.