With the amount of hypericin extracted as the response value, response surface methodology was used to study and optimize the effect of hypericin in hypericum attenuatum. The optimal extraction process was obtained. The cytopathogenic effect (CPE) method was used to detect the anti-infectious bronchitis virus (IBV) effects of hypericum attenuatum. The results showed that a mathematical model for ultrasonic extraction of hypericin from hypericum attenuatum was established，and the optimum conditions for extracting hypericin by ultrasound were as follows: extraction temperature 40.5?C, acetone concentration 69.5%, extraction time 43.5 min, ratio of liquid to material 15.3, and the extraction rate of hypericin was 4.70mg/. g, consistent with the theoretical value. The main effect relationship was extraction time > acetone concentration > extraction temperature > liquid to material ratio. The extract of hypericum attenuatum extract before, after and at the same time when cells were infected with IBV significantly inhibited the effects of CPE. It showed that the ultrasonic extraction process of hypericum attenuatum choisy was reliable, and the extractive amount of hypericin was much higher than that of routine extraction method. Hypericum attenuatum choisy had a good anti-IBV effect.