The invention belongs to a low-temperature carbide furnace for producing continuous carbon fiber, which comprises a furnace body, a hearth in the furnace body, a thermal-insulation layer, a refractory layer, a heating element and an exhaust pipe, wherein the thermal-insulation layer, the refractory layer and the heating element are arranged in turn between the furnace body and the hearth; the exhaust pipe is arranged on the furnace body, runs through the hearth and the atmosphere; an included angle of 2 to 30 degrees is formed between the hearth upper wall face close to a fiber bundle inlet and a horizontal plane; and the height of the hearth upper wall face at the position increases linearly along the operation direction of a fiber bundle. In the invention, the technical problems of unsmooth waste gas exhaust and waste gas accumulation caused by an unreasonable hearth structure of the conventional carbide furnace in fiber carbonization are solved. The carbide furnace ensures the stabilization and continuity of a pre-oxidation fiber carbonization process and improves carbon fiber production efficiency.