Abstract: Objective: Orthogonal experiment is used to optimize the extraction process of total flavonoids from fermented centipede powder.Method: Regarding the yield of total flavonoids from fermented centipede as the research index.On the basic of single-factor test, the ultrasonic-assisted extraction process parameters of total flavonoids from fermented centipede including the ratio of extractive temperature ( A) , the ratio of material ( B) and extractive time ( C) were optimized by orthogonal test and the yield of total flavonoids was used as the responsive values. The antineoplastic activity of extraction to lung adenocarcinoma cell A549 were measured by using MTT assay in vitro.Result: The order of the effect of these factors on the yield of total flavonoids from fermented centipede powder was the ratio of material > extractive temperature > extractive time.In this experiment, the best extractive process was under 80 ℃ of the extractive temperature, 1 ∶ 40 ( g ∶ m L) of the ratio of material, 2.5 h of the extraction time.Under these conditions, the yield of total flavonoids was 1.970%. The inhibition ratio of different concentration of alcohol extraction of fermented centipede powder to lung adenocarcinoma cell A549 was all greater than cis-platinum, and it had good antineoplasmic activity.