The invention relates to a production method for petrifaction gas. The invention comprises the steps that firstly, decomposition: lime stone is hated and decomposed, and carbon dioxide and calcium oxide are generated; secondly, reaction: the carbon dioxide and the calcium oxide generated in the step one are used as raw material, carbon and water are added into the raw material, at 900 to 1300 DEG C, to react to generate carbon monoxide, hydrogen gas, methane, and calcium carbide; thirdly, filtration: mixed gas generated in the step two is filtered, combustible gas, namely, the carbon monoxide, the hydrogen gas, and the methane, are separated and collected, and the by product in the mixed gas is classified and collected. The invention provides the production method for high and new energy source petrifaction gas, in production process, generated tail gas is also collected, wherein most of tail gas can be used as fuel again, and nitrogen gas which is not burned can be also used as the raw material for carbamide production. Therefore, the invention can provide a great number of novel energy sources, and has positive function to the lack of energy source reparation.