Preparation method of graphene

The invention discloses a preparation method of graphene. Specifically, graphite oxide prepared by existing technology is dispersed in a green reducing agent, and oxygen on the graphite oxide is removed through an unbalance reaction in hot water, so that the graphite oxide is reduced into graphene. The graphene prepared by the method provided by the invention has low oxygen content and high conductivity; the method has advantages of simple operation, low cost and high efficiency, and really realizes graphene preparation in kilogram level; no reducing agent severely harmful to the environment or strongly toxic is used; therefore, the method causes no environmental pollution, greatly simplifies the growth process, suits industrial production, and has potential application value in the fields based on graphene.