The utility model relates to a suction nozzle used on a vacuum circulating degasser, which is provided with a cylindrical body, and the front area of the body is provided with a truncated cone which is gradually contracted inward. The suction nozzle can avoid the front part of the suction nozzle from being directly eroded by sinters and molten steel and can effectively prevent the front magnesite-chrome brick from being stripped or broken, so the suction nozzle with the structure has a relative long service life, the suction nozzle provided by the utility model can be repetitively used one hundred and five times, so the service life of the suction nozzle is more than three times longer than the prior suction nozzles.