TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The corncob mushroom residue is waste mushroom residue of the edible mushroom cultured by corncob as main raw material, where the moisture content is 40-50 wt.%. The edible mushroom is needle mushroom, oyster mushroom, Lentinus edodes or straw mushroom. The moisture content of the pig manure is 75-85 wt.%, carbon to nitrogen ratio is (13-14) to 1; the moisture content of the cow dung is 80-83 wt.%, and the carbon ratio is 25 to 1. The biogas slurry is the supernatant biogas slurry in the methane tank with animal excrement as raw material for normally producing methane by fermentation. Preferred Method: The method comprises: (i) crushing block corncob mushroom residue into particles with uniform aperture; fully soaking in the water and soaking with 10 wt.% ammonia for water 150-200 kg/ton mushroom residue for 20-24 hours; stirring for 5 minutes in every other 2-3 hours during soaking; cleaning the mushroom residue after soaking until the pH is 7.5-8; (ii) stacking the corncob mushroom residue treated in step (i) according to the manner of one layer of corncob mushroom residue, one layer of pig manure or cow dung; uniformly adding methane microbial inoculum after dissolving by water into the feeding stack; covering plastic cloth on the feeding stack, where the time for stacking is 5-10 days; and turning the stack in every other 1-2 days; (iii) throwing the raw material for fermentation treated in step (ii) into the methane tank for user or anaerobic reactor, where the amount of raw material is 80-100 kg/m3; using biogas slurry 10-15 vol.% of the methane tank for user as inoculum for initial using; adding water until it is up to 75-80 vol.% of the methane tank; stirring and fully mixing; or adding biogas slurry 0.33 volume of the methane tank in the anaerobic reactor for initial using as inoculum for starting and adding water for adjusting until the concentration of the total solid in the mixture is up to 10 wt.%. The time for stacking in step (ii) is determined by air temperature; 5-7 days are suitable for summer with high temperature, and 7-10 days is suitable for spring and autumn.