The invention discloses a preparation method of an ezetimibe tablet. The preparation method comprises the following steps of (1) dissolving hydroxypropyl cellulose and ezetimibe into ethanol, and dissolving a carrier material mannitol into a water solution; (2) respectively introducing a supercritical carbon dioxide fluid and the two solutions into a coaxial three-channel nozzle by setting the pressure and temperature of the supercritical carbon dioxide fluid to 10-50 MPa and 35-60 DEG C, and acquiring ultrafine granule mixed powder which contains the ezetimibe, the hydroxypropyl cellulose and the mannitol by utilizing the anti-solvent effect of the supercritical carbon dioxide fluid; (3) directly tabletting the ultrafine granule mixed powder and pharmaceutically acceptable auxiliary materials. The method disclosed by the invention can be used for fast dissolving the ezetimibe, can achieve the dissolution rate of the ezetimibe tablet by 95% for 5 minutes and does not contain the surface active agent.