The invention discloses a method for preparing grapheme through organic amine solvothermal method, which comprises the following steps: 1) adopting the solvothermal method to lead expanded graphite to react with organic amine or organic amine solvent to obtain the semi-discrete liquid of grapheme; 2) implementing ultrasonic dispersion and then implementing centrifugation on the semi-discrete liquid of grapheme obtained from the step 1), and then collecting supernate, thus obtaining the grapheme. The invention obtains the grapheme by taking solvent thermal spalling as a means. A scanning electron microscope, a transmission electron microscope, and an atomic force microscope are adopted to represent the topogram of the grapheme; a Raman spectrum and an X-ray photoelectron spectroscopy are used to represent the density of imperfection and oxidation situation of the grapheme. The result shows that the grapheme synthesized by the method of the invention has the advantages of small size, high quality, less defects, light oxidation degree, etc. besides, the method for preparing grapheme through organic amine solvothermal method also has the advantages of simple synthetic route, low cost, high concentration and uneasy accumulation of the synthesized discrete liquid of grapheme, and excellent application prospect on the aspect of discrete liquid of grapheme materials.