NOVELTY - Producing marsh gas involves crushing perishable organic waste and straw and filling in filter material on solid infiltration bed, adding marsh gas fermentation inoculum, carrying out anaerobic hydrolysis acid production to form filtrate; and collecting and discharging from solid infiltration bed at bottom of filtrate, adding water to straw pre-treating reactor and straw after crushing, carrying out heating and immersing; and collecting straw, after hydrolysis acid production residues and pre-treated into biogas fermentation reactor, and performing mixing anaerobic fermentation marsh gas.    USE - For producing marsh gas which is used for power generation (claimed).    ADVANTAGE - The method reduces the straw pre-processing cost; and improves the marsh gas fermentation performance.    DETAILED DESCRIPTION - Producing marsh gas using a perishable organic waste and straw, involves collecting perishable organic waste and straw, and crushing; filling the crushed perishable organic waste and straw in the filter material on the solid infiltration bed, adding marsh gas fermentation inoculum; controlling the pH value of 4.5-6.5 to carry out anaerobic hydrolysis acid production to generate volatile fatty acid and a little hydrogen and carbon dioxide; adding perishable organic waste into biogas slurry from the solid infiltration bed to form the penetrating fluid through a porous plate filter filler and supporting a filter filler; collecting and discharging the penetrating fluid from the bottom of the solid infiltration bed, adding straw back to in the straw pre-treating reactor, stirring uniformly, controlling the straw dry mass concentration in 10-15%, and carrying out pre-heating and immersing the sealed straw pre-treating reactor; and collecting the solid infiltration bed part, adding water to biogas fermentation reactor, adding biogas slurry for diluting volatile fatty acid concentration or adding little alkali for adjusting to neutral, and adding biogas fermentation inoculum for mixing anaerobic fermentation, collecting the hydrogen discharged from the solid infiltration bed top part and carbon dioxide, and collecting marsh gas from the bottom of fermentation reactor for marsh gas fermentation, where a control biogas fermentation temperature is 25 degrees C to -60 degrees C, and the pH value is 6.5-8.