The invention relates to a preparation method of a high-thermal-conductivity graphene floor heating floor. The method comprises the following steps of 1 single plate pretreating, 2 air drying at roomtemperature, 3 plasma treating, 4 dipping, 5 drying, 6 single plate blank matching and 7 hot pressing. According to the preparation method, a graphene-metal composite material is dissolved into a dipping solution, dipping modification is conducted on wood, the graphene-metal composite material is evenly distributed in wood cell cavities, therefore, the thermal conductivity of the wood can be greatly improved, and the density and the stability of the wood can be enhanced. The modified wood is made into the high-thermal-conductivity graphene floor heating floor by being taken as a veneer layer,a middle layer and a substrate, the thermal conductivity of the floor is effectively improved, and the functions of saving energy and reducing consumption and being uniform in thermal dissipation, stable in structure and the like of the floor heating floor are achieved.