NOVELTY - Extracting equol from biogas liquid of fermented chicken manure, comprises (i) fermenting chicken manure biogas, concentrating under reduced pressure, extracting biogas liquid concentrate by adding solvent, and extracting with petroleum ether, concentrating, and extracting with ethyl acetate, extracting with n-butanol, and passing through silica gel column chromatography; and (ii) adding chloroform/methanol solution gradient elution, and carrying out thin layer chromatographic (TLC) by using an eluting liquid, and detecting the combined results, and concentrating by LH-20 gel chromatography.    USE - The method is useful for extracting equol from biogas liquid of fermented chicken manure (claimed).    ADVANTAGE - The method has mild processing condition, and simple operation procedure; produces high purity product; directly extracts from biogas; circulates extracting agent to facilitate repeated utilization effect; and is economical.    DETAILED DESCRIPTION - Extracting equol from biogas liquid of fermented chicken manure, comprises (i) fermenting chicken manure biogas at room temperature of 50-70 degrees C, concentrating under reduced pressure until the moisture content reaches 70-85%, to obtain biogas liquid concentrate, and extracting biogas liquid concentrate by adding a solvent in a mass ratio of 1:2, and carrying out extraction process for first time for 6 times by using petroleum ether, concentrating the petroleum ether extract, and extracting biogas liquid concentrate for 6 times by adding ethyl acetate, concentrating the ethyl acetate extract, and extracting the biogas liquid concentrate again for 6 times by adding n-butanol, collecting, and concentrating to obtain n-butanol extract, and passing portions of n-butanol extract and biogas liquid concentrate through 300-400 meshes silica gel column chromatography; and (ii) sequentially adding chloroform/methanol solution gradient elution in an amount of 30:1, 25:1, 20:1, 15:1, 10:1, 5:1 and 1:1, and carrying out thin layer chromatographic (TLC) by using an eluting liquid, and detecting the combined results, and concentrating, collecting fractions of n-butanol in ratio of 25:1 and 20:1, and concentrating fractions of n-butanol by LH-20 gel chromatography by using 100% methanol solution during isocratic elution process, to obtain S-equol.