Response surface methodology (RSM) based on Box Behnken Design (BBD) was employed to optimize the extraction conditions including the liquid-to-solid ratio, ultrasonic time, ethanol concentration and extraction time. The optimized conditions were as follows: liquid-to-solid ratio 1∶22 (g/mL), ultrasonic time 3 min, ethanol concentration 80% and extraction time 78 min. Under these conditions, the experimental yield of lignans and polyphenol were 44.89 mg/g, 48.17 mg/g, respectively.