Abstract: Extracting total flavonoids in pigeon pea leaves by ultrasonic method.Analysis the factors which ultrasonic extraction time, the concentration of ethanol and the solid-liquid ratio condition and L9 (34) orthogonal, to find the optimal conditions of extraction of total flovonoids in pigeon pea leaves.From the orthogonal results of ultrasonic extraction, the optimal conditions of extraction of total flavonoids in pigeon pea leaves are as following: 20min ultrasonic extraction 70%ethanol, 1∶30solid-liquid ratio.With above extraction condition the yield of total flavonoids is 3.65%.The average recovery of the detection method is 99.01%-102.72%, the method has excellent stability and repeatability.