Abstract: Using the residual heat of synthesis gas as the heating source for methane fermentation heating could raise the thermal efficiency of gasifying by 10%～15%. Mixing the scrubbing coolant of synthesis gas with the slurry from cattle manure could solve the problem of pollution which would be posed by the scrubbing fluid itself.The paper discussed the effect of phenol material in the scrubbing coolant on methane fermentation and the use of methane fermentation broth as fertilizers based on three criteria,i, e. quality analysis of the scrubbing coolant,methane fermentation test and removal of tar and soot in synthesis gas. It was found that it would be feasible to adopt the direct heat exchange method utilizing the exothermic heat of synthesis gas as the heat source for methane fermentation.