The invention provides a method for preparing grapheme on the basis of controlling ion implantation energy. As per the method provided by the invention, firstly, acrbonic ions are implanted into a catalytic substrate based on at least on implantation energy; then the catalytic substrate implanted with acrbonic ions is subjected from annealing so as to enable the acrbonic ions to be separated out, and at least one grapheme thin layer is formed on the surface of the catalytic substrate; and finally, the catalytic substrate with the grapheme thin layer on the surface is removed so as to obtain at least one grapheme thin layer. The grapheme prepared by the method has good quality, large size and controllable layer number, is easy to transfer compared with a SiC (suppressed ion chromatography) sublimed method, and has controllable layer number as compared with a chemical vaporous depositon method.