The invention discloses a high-conductivity calcined petroleum coke and a preparation method thereof. The high-conductivity calcined petroleum coke contains the following raw materials in parts by weight: 78.0-83.0wt% of calcined petroleum coke, 5.0-10.0wt% of flake graphite powder, 3.0-4.0wt% of water-soluble cellulose ether, 2.5-4.5wt% of calcium oxide, 2.5-3.5wt% of copper chloride and 0.8-2.0wt% of sodium silicate. By means of the high-conductivity calcined petroleum coke, the problem that waste anode carbon blocks are recycled in the metal aluminum production industry is solved, waste materials are changed into things of value, and the calcined petroleum coke is especially suitable for being used as a low-resistivity grouting material in earthing engineering, particularly in earthing engineering of an electric power system.