The pressure-free double-layer steam furnace is improved on the basis of the original pressure boiler function, the practical gas making equipment, the steam furnace through the rational design of the efficiency of the traditional boiler than the original 5-8 times, environmental protection and energy efficiency greatly improved. Its working principle is based on the production of steam, from the original non-temperature up to 100 degrees, through the steam, the temperature rose to 700-1000 degrees, the natural elimination of excess gas, no pressure safety, through its own mixing package again shortened Steam time, easy maintenance, simple structure, water level design is reasonable, the price is a new generation of plastic equipment, but also according to the different requirements of customers plus design and processing.