The invention relates to a method for preparing graphene by using an anode material of a waste aluminum ion secondary battery, being an efficient method for recycling the anode material graphite of a waste aluminum ion battery, and belonging to the fields of waste battery recycling and advanced material preparation. According to the method, the waste aluminum ion battery taking a graphite structure material as an anode is used, and the graphite anode of the waste battery is directly changed into the graphene to be recycled in an electrolytic way; a principle of the method is that aluminum complex ions in ionic liquid are enabled to be continuously embedded into a carbon layer under high potential, a layered structure of the graphite is further cracked, and the high value-added graphene is produced.