▎ 摘　　要

NOVELTY - Preparing graphene comprises adding ionic liquid into a solvent in a mass ratio of 1:1-1:5 and dispersing ultrasonically to obtain an ionic liquid solution, adding expandable graphite into the ionic liquid solution in a mass ratio of 1:1-1:5 and dispersing ultrasonically to obtain a suspension, reacting the suspension in a sealed reactor at 240-400 degrees C under 5-25 MPa for 10-60 minutes, and then unloading the pressure of the reactor. USE - The method is useful for preparing graphene (claimed).