Objective To establish a method for the determination of multi-component content of prepared Polygoni Multiflori Radix extract,and to compare the changes of chemical components in the decoction process of prepared Polygoni Multiflori Radix powder decoction pieces and traditional decoction pieces,so as to provide scientific basis for the preparation and clinical application of traditional decoction pieces.Methods The contents of gallic acid,5-hydroxymethylfurfural,2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside,emodin-8-O-β-D-glucoside,physcion-8-O-β-D-glucoside and emodin were determined by high performance liquid chromatography(HPLC).With the extraction rate and alcohol-soluble extract as evaluation indexes,the effects of standard decoction method and non-standard decoction method on the extraction of prepared Polygoni Multiflori Radix powder decoction pieces and original decoction pieces were investigated.Results Non-standard decoction boiling method:the contents of gallic acid,5-hydroxymethylfurfural,2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside,emodin-8-O-β-D-glucoside,physcion-8-O-β-D-glucoside and emodin in the prepared Polygoni Multiflori Radix powder decoction pieces were significantly increased,and the increase ratios were 71.18%,141.67%,146.29%,150.00%,625.00%and 296.00%,respectively.In particular,physcion-8-O-β-D-glucoside increased by 7.25 times.Standard decoction boiling method:the content of the above index components in the prepared Polygoni Multiflori Radix powder decoction pieces was significantly increased,and the increase ratios were 28.09%,10.53%,66.01%,45.45%,316.67%,and 65.85%,respectively.In particular,physcion-8-O-β-D-glucoside increased by 4.17 times.The relative standard deviation(RSD)of each index content of prepared powder decoction by standard decoction boiled method was within 10%.Conclusion The dissolution and quality uniformity of the index components of the prepared Polygoni Multiflori Radix powder decoction pieces are superior to those of the original decoction pieces,which can improve the accuracy of clinical medication and need to be reduced as appropriate.