The invention relates to a graphene preparing method, in particular to a high-conductivity graphene preparing method. The method is used for solving the problems that according to an existing preparing method, low-cost batched production can be difficultly achieved on the graphene with the stable performance and high conductivity, many steps exist, and factors influencing the product stability in the preparing process are multiple and complex. According to the scheme, the method includes the steps that firstly, expansible graphite is heated, and the expanded graphite is prepared; secondly, the expanded graphite is stripped off under the double action of organic matter with low surface tension and ultrasounds, impurities are removed through secondary centrifugation, secondary centrifugation sediment is dried, and high-conductivity graphene is obtained. The high-conductivity graphene preparing method has the advantages that the expanded graphite is stripped off under the double action of the organic solvent with the low surface tension and the ultrasounds, a redox reaction does not exist, impurities are not introduced, and compared with a traditional chemical preparing method, the generated graphene is few in defect, few in layer and higher in conductivity; a special device is not needed, the preparing method is simple and convenient, the stability of the performance of the prepared graphene is good, the performance is good, and industrial production is facilitated.