The KANS safety door interlock devices approved by National Labor Safety Inspection Department and door with no pressure and dual fail-safe are adopted in the series of products so as to insure safely of use. The saturated steam is used as the heating medium in the boilers so as to make up the pressurized air to carry out counter-pressure operations. (The superheated water can also be used as the heating medium if partial change of pipes). Cold water (lukewarm water) is filled directly to cool forcibly. It is appropriate for the sterilization of different packages and different foods. The product possesses the advantages such as easy operation, low cost and is the most all-purpose sterilization equipment in the industrial production of food.