The invention relates to the usage of a 2',5',6',7'-tetrahydroxyflavanonol and the derivative in treating pyohemia, belonging to flavanonol compound THF, which is extracted and separated from baikal skullcap root of Chinese herbal medicine. Through experiment showing, the THF has the advantages that: the THF has direct neutralization effect and reveals better dose effect relationship; the THF also reveals better dose effect relationship upon inhibition of RAW 264.7 cells activation LPS stimulation; the THF can lower LPS level in blood of LPS blood symptom model animal in vivo; the THF also has obvious protection effect upon bacterial sepsis model mouse caused by heat-inactivation escherichia coli with lethal dose; the THF has good application prospect under the condition of lacking effective means treating pyohemia in prior study.