Double airflow supersonic plasma spray gun

The invention provides a double airflow supersonic plasma spray gun comprising a cathode rod, an arcing intermediate pole, an acceleration intermediate pole and an anode. Theanode is provided with a powder feeding mouth. The arcing intermediate pole, the acceleration intermediate pole and the anode are internally and coaxially provided with cavity channels which are communicated with each other and used for penetration of plasma airflow. The cathode rod is arranged in an insulated rear base. One end, which is close to the arcing intermediate pole, of the cathode rod is provided with a tungsten cathode and an argon gas distribution ring which is used for piping of argon. The insulated rear base is internally provided with a high frequency generator connector and an argon input channel which is communicated with the argon gas distribution ring. The arcing intermediate pole and the acceleration intermediate pole are arranged on an intermediate pole base, and an air gas distribution ring used for piping of mixed gas formed by air and combustible gas is arranged between the arcing intermediate pole and the acceleration intermediate pole. A problem of short service life of the cathode of pure air supersonic plasma equipment is solved, and production cost is greatly reduced in comparison with that of pure argon supersonic plasma equipment. Besides, plasma temperature and speed can be adjusted through ratio of air to combustible gas so that technology performance is high.