Objective:To study on preparation technology of dry extract from Pueraria thomsonii.Method:Extraction technology of P.thomsonii was optimized by single factor and orthogonal experiment by taking the content of puerarin as index.Technology steps of dry extract from P.thomsonii was estimated by the content of puerarin and transfer rate of main feature peak area of specific chromatogram as index.Result:Optimum extraction technology was established as follows:heating reflux extracted 3 times with 8 times the amount of 30% ethanol for 2 h each time

extraction ratio of puerarin was more than 97%;Main preparation technology steps were:decoction pieces→alcohol extract fluid→concentrated solution→alcohol precipitating fluid→extract→dry extract

transfer ratio of puerarin in technology steps were 97.89%±2.17%

81.70%±2.12%

74.92%±1.92%

72.15%±1.06%

50.64%±2.57%（n=3）

it showed puerarin losed more in drying step;It showed in specific chromatogram that all technology steps remained 7 characteristic peaks of fingerprint

and transfer ratio of peak 1 and peak 6 was high

but it was low of peak 2

3

4

5

7;Yield of dry extract from P.thomsonii was 5.09%±0.06%

and the content of puerarin was（29.262±1.500） mg·g-1.Conclusion:This technology was simple

feasible and could provide a reference for technology of P.thomsonii compound preparation.