Abstract: In order to improve the comprehensive development and utilization of kudzu root resources,the simultaneous extraction of flavonoid and polysaccharide assisted in combination ultrasonic field from kudzu root were investigated.The results showed that extraction methods assisted by combined ultrasound were better than that assisted by the single frequency ultrasound. And the sequential combined ultrasound was superior to simultaneous combined ultrasound in extraction. Under the optimum condition of the total ultrasonic power 600 W,extraction time 20 min,the ratio of liquid to solid 30 m L / g,temperature 50℃,sequential combined ultrasonic frequency of 15 k Hz and 20 k Hz,the flavonoids and polysaccharide extraction rate reached 8.72% and 2.18% from7.92% and 1.91%,which increased by 10.10% and 14.14% respectively compared with 20 k Hz single frequency ultrasound assisted extraction.