The present invention discloses a novel use of benzopyran compound, preparation of benzopyrone hamaudol and sec-O-Glucosylhamaudol, and an extract containing a rich benzopyran lactone, a preparation method, and a medical use thereof. The invention provides a use of benzopyrone for attenuating aristolochic acid and a traditional Chinese medicine containing aristolochic acid, a use of benzopyran lactone for attenuating aristolochic acid and a traditional Chinese medicine containing aristolochic acid, a method for preparing benzopyrone hamaudol and a method for detecting optical isomer thereof, a culture method for improving the content of sec-o-glucosylhamaudol in wind-resistant callus, and an extract containing a rich benzopyran lactone, a preparation method, and a medical use thereof.