The invention relates to the field of new material, in particular to a method for preparing graphene, i.e. an electrochemical stripping method. The method comprises the steps of: firstly, assembling a battery by a pole piece containing graphite material, a counter electrode pole piece containing lithium, electrolyte containing propylene carbonate (PC) and a diaphragm, leading solvent lithium ions to be embedded among the layers of the graphite by discharging or charging, and finally, stripping the graphite layer by layer and forming the graphene. Compared with the prior art, the method takes full account of the characteristics that the graphite is incompatible with the PC and the lithium ions can be inserted into the graphite layer by layer during charging or discharging, so that the solvent lithium ions can be inserted into the graphite layer by layer, and the graphene can be finally generated after the graphite is stripped. According to the method for preparing the graphene by electrochemical stripping, complicated expensive equipment can be omitted, the operation is simple, the graphene can be obtained by simple charging, discharging and aftertreatment, therefore, the method is safe, reliable and lower in cost, and industrialized production can be easily formed.