The invention provides a compound named as 3,5-bis(3,4-dihydroxyphenyl)pyridine. The compound is capable of eliminating oxygen free radicals and has wide application prospects in the treatment of diseases relevant with cell breaking capacity of free radicals of a human body. The invention further provides an extraction method of 3,5-bis(3,4-dihydroxyphenyl)pyridine. The extraction method comprises the steps of firstly carrying out cold-soaked extraction on blaps rynehopetera fairmaire powder so as to obtain an extracting solution, and carrying out extraction, first silica gel column chromatography separation, ODS reversed-phase column chromatography separation and second silica gel column chromatography separation, so as to obtain 3,5-bis(3,4-dihydroxyphenyl)pyridine. The extraction method has the beneficial effects that the steps are simple, the cost is low, the raw material sources are wide, and industrial production is easily realized.