Taking Hunan pomelo fruit drop as raw materials, ethanol ultrasonic extraction of flavonoids pomelo, Research AB-8, NKA-9, D110 and ADS-17 four types of macroporous resin separation and purification process optimization pomelo flavonoids. The results showed that: AB-8 macroporous highest amount of total flavonoids Hunan pomelo, reaching 0.70 mg/mL; integrated adsorption, recovery, purity and absorption rate and other indicators, AB-8 macroporous resin separation and purification of the Hunan Xiang optimal conditions grapefruit flavonoids was: 110 aspect ratio; the adsorption velocity 1.5 BV/h, the eluent pH value 4.0, eluent 70% ethanol eluted dosage 4 BV, analytical flow rate 2 BV/h, the resin was repeated 3 times.