When the temperature reaches the set temperature, the temperature controller automatically turns off the blower to stop the automatic sealing of the air supply shaft. When the temperature is lower than the set temperature, the temperature controller automatically turns on the blower to continue to deliver hot air. The double layer design of the inner liner (the secondary backburning chamber is more energy-saving) isolates the boiler combustion chamber from the hot air outlet, and uses a fan to blow out the temperature between the interlayer for heating. The soot goes out along the chimney (so that the hot air sent to the room is pollution-free, fresh and natural), and the fan blows the sandwich heat out to the room for heating, which can realize the functions of automatic heating, automatic air supply and automatic combustion.