Extracting technique assisted by ultrahigh pressure extraction method of flavonoids from hawthorn was optimized. The total yields of rutin,hyperin,and quercetin were used as response value,ethyl alcohol volume percentage,liquid to solid(L/S) ratio,power,and retention time were investigated in this experiment.The results showed that the sequence of different factors on flavonoid yield was:ethyl alcohol volume percentage>retention time>L/S ratio>power;and the mathematical model of ultrahigh pressure extractio...