Flavonoids were extracted from Brassica napus L.bee pollen by ultrasonic-microwave synergistic method.The effects of alcohol concentration,extraction time,liquid-solid ratio,and microwave power on the extraction yield of total flavonoids were studied.The optimal extraction conditions determined through single-factor and orthogonal experiments were as follows:alcohol concentration 90%,liquid-solid ratio 30∶ 1,microwave power 260 W and extraction time 180 s.Under the above conditions,the extraction yield of total flavonoids was up to 3.36%.Compared with hot reflux extraction,ultrasonic and microwave extraction,ultrasonic-microwave method had obvious high efficiency.Moreover,ultrasonic-microwave method had the advantages of low energy consumption and safe.LC-MS analyses exhibited that four kinds of flavonoid aglycones were identified in the ultrasonic-microwave synergistic extraction of Brassica napus L.bee pollen:Quercetin-3-O-β-D-pyranoid glucose base-(1 → 2)-β-D-pyranoid glycosidase,Kaempferol-3,4 '-double-O-β-D-pyranoid glycosidase,Isohtamnetin-3-O-β-D-pyranoid glucose base-(1 →2)-β-Dpyranoid glycosidase and Kaempferol-3-O-β-D-pyranoid glucose base-(1→2) β-D-pyranoid glycosidase.