Abstract: The present invention relates to a method and a device taking gas as fuel in industry, dining halls, power plants and the like, in particular to an energy-saving, high-efficiency and environment-friendly method and a device for gas combustion. The energy-saving method for gas combustion is characterized in that: the combustion method is that: 1. gas enters into a hearth for one time or times of compression and expansion; 2. air is introduced into the hearth and is mixed with the gas; 3. the gas is ignited, the volume of the gas and the volume of the air are rapidly expanded and compressed in the hearth, and the bonds of gas molecules are cracked; 4. the gas rotates in the hearth at a high speed, and is fully combusted in a stove body to emit heat; and 5. when the gas is combusted, the gas is preheated before entering into the hearth. The present invention further discloses a device for realizing the method.