The invention discloses a method for preparing calcium carbide, which comprises the following steps: drying a carbon-base raw material to obtain a dried carbon-base raw material; respectively crushing the dried carbon-base raw material and a calcium-base raw material to obtain a carbon-base powder and a calcium-base powder; mixing the carbon-base powder and calcium-base powder to obtain a mixture; forming the mixture to obtain a lump material; pyrolyzing the lump material to obtain high heating value synthetic gas, tar and a pyrolytic solid product, wherein the pyrolytic solid product contains coke, semicoke, carbon black and quicklime; and feeding the pyrolytic solid product into an arc furnace at the temperature of not lower than 450 DEG C to perform smelting in the arc furnace, thereby obtaining the calcium carbide. The method can obviously lower the smelting energy consumption and production cost, and further enhances the preparation efficiency and quality of the calcium carbide.