Abstract: The objective of the study was to optimize extraction technology of ultrasonic/microwave assisted extraction(UMAE) and to explain the reason for high-efficiency of this technology. The technology optimization was completed by the single factor experiment and orthogonal experiment of L9( 34). The reason for high-efficiency was explained by the comparison experiment,splitting analysis and scanning electron microscopy(SEM). The results of the optimal parameters of UMAE technology were the extracting time 5 min,the microwave power 125 W,the concentration of ethanol 70%,the solid-liquid ratio 1∶30 g/m L and the ultrasonic power 50 W(open). Comparison experiment indicated that the extraction ratio of total flavonoids from lotus leaf by UMAE was significantly higher than that of water bath shaking extraction( WBSE) under both optimum conditions(p<0.001). It was also found that the highly efficient extraction of UMAE was simultaneously acted and mutually reinforced by ultrasonic and microwave by the splitting analysis. The materials and cell walls were more seriously destroyed so as to achieve higher extraction efficiency. UMAE was a extraction technology with high efficiency and worth of further research and development.