The invention discloses super-clean graphene and a preparation method thereof. The preparation method of the super-clean graphene comprises the following steps: putting foam copper on a copper substrate, and attaching; leading carbon source gas and hydrogen to perform chemical vapor deposition; after deposition is completed, obtaining the super-clean graphene at the contact surface of the copper substrate and the foam copper. The preparation method has the advantages that the preparation method is simple and is suitable for large-scale production, the continuous clean area reaches the sub-centimeter level, and the preparation method is suitable for the fields of electronics, optics and the like.