The invention discloses a non-pressure heating structure capable of stably outputting boiling-point high-temperature liquid. The non-pressure heating structure comprises a heating cavity, a heating body is arranged in the heating cavity, a liquid inlet is formed in the position, close to the bottom, of the heating cavity, an overflow upper edge opening is formed in one side of the upper end of the heating cavity, a separation buffer cavity is formed in the outer side of the overflow upper edge opening, and a liquid outlet is formed in the lower portion of the separation buffer cavity. The invention has the advantages that: 1, the liquid outlet temperature of the structure is determined by the physical
boiling point of liquid, the liquid is not boiled and vaporized, and gas-liquid mixed fluid cannot
climb over the upper edge opening of the heating cavity, so that the liquid is not discharged, and the liquid outlet temperature is the
boiling point temperature and is constant; 2, when the
heating energy is stably input, the output flow of the high-temperature liquid is stable and sustainable; 3, according to the output of the high-temperature liquid in the structure, under the condition that the low-temperature liquid inlet supply condition is constant, the flow of the high-temperature liquid is controllable by controlling the input level of
heating energy, and when heating is stopped, the output of the high-temperature liquid is also stopped; and 4, the whole structure is communicated with the
atmosphere, so that no-pressure safety is always realized during operation.