Abstract: An ultrasonic-microwave alternant method for extracting dihydroquercetin from larch wood was applied by using dihydroquercetin yield as an index. The extraction was conducted using 60% ethanol as solvent，the solid to liquid ratio of 1∶12，and soakage time of 3 hours. The microwave treatment time was 10 min，ultrasonic treatment time was 40 min respectively and the extraction was performed one time with the strongest power. The ultrasonic-microwave alternant extraction was performed by ultrasonic extraction for 40 min and then microwave extraction for 10min. The yield of dihydroquercetin with ultrasonic and microwave extraction were 0.034% and 0.074% respectively，while that of ultrasonic-microwave alternant extraction was 0.12% which is much higher than ultrasonic and microwave extraction alone. By scanning electron microscopy (SEM) observation，the ultrasonic-microwave alternant effect of substance dissolution from plant cell was the most obvious among the above-mentioned three methods.

摘要： 以二氢槲皮素的得率为指标，采用超声-微波交替法从落叶松中提取二氢槲皮素。以体积分数60%乙醇作为提取溶剂，料液比1∶12，浸润3 h，强档功率提取1次，微波提取10 min，超声提取40 min，超声-微波交替提取的条件为超声提取40 min后再微波提取10 min。二氢槲皮素单独超声和微波提取时得率分别为0.034%和0.074%，超声-微波交替提取时得率可达0.12%，明显优于单独超声或微波提取。通过扫描电子显微镜观察超声提取、微波提取和超声-微波交替提取所得的物料，超声-微波交替提取的抽提效果最为明显。