The quercetin-7-O-β-D-glucuronic acid compound in the branches and leaves of Potentilla fruticosa L. was extracted and separated,and its chemical structure was identified by ¹³C NMR.It was prepared by AB-8 macroporous adsorption resin and semi-preparative high-performance liquid chromatography. Purification and enrichment.Finally,an enzyme inhibitor screening model with 4-nitrophenol-α-D-glucopyranoside (pNPG) as a substrate is used to detect the activity of the target compound and the type of inhibitor.The results showed that the ethanol of 20% macroporous adsorption resin (AB-8) contained quercetin-7-O-β-D-glucuronide.After preparative high-performance liquid chromatography and high-performance liquid chromatography,the quercetin -7-O-β-D-glucuronide was obtained at 2481.8mg,purity 97.95%.The activity test results showed that the maximum inhibitory rate of quercetin-7-O-β-D-glucuronide against α-glucosidase was 94.6 7%,IC₅₀ was 0.259 mmol/L,and the inhibition rate was significantly higher than of the positive control drug acarbose,and the inhibitor type was competitive inhibition.