The invention discloses a preparation method and an application of high-bioavailability Pummelo Peel extract. The method comprises the following operating steps: 1, preparing an extract solution from commercial Pummelo Peel extract; 2, carrying out glycosidase catalytic glycosylation on the extract; 3, carrying out membrane separation and concentration on the above obtained glycosylation product; and 4, drying and collecting high-bioavailability glycosylated Pummelo Peel extract. The application is the application of the high-bioavailability Pummelo Peel extract in the production of medicinal preparations, healthcare products or special formula foods. The high-bioavailability Pummelo Peel extract realizes the glycosylation of Pummelo Peel extract flavones through a biological enzyme conversion technology, so the solubility in water and the in-vitro dissolve-out speed of the Pummelo Peel extract are improved, and the bioavailability is improved.