The invention discloses a continuous carbonization furnace and a method for continuously producing coarse-grained carbide powder. The furnace is a tunnel type and boat propulsion type furnace, and consists of a furnace end, a low-temperature deoxidizing area, a high-temperature carbonizing area and a furnace tail in sequence, wherein a furnace tube of the low-temperature deoxidizing area is made of heat-resistant steel or ceramic, and is heated by using an electric heating element; a heat-preserving material is an organic non-metallic refractory material; the temperature is controlled separately, and is lower than the working temperature of the high-temperature carbonizing area; a reducing gas H2 serving as a working medium is introduced; a non-oxidizing gas serving as a protective gas is input into the furnace tube of the high-temperature carbonizing area; and the protective gas flows through the furnace tail, the high-temperature carbonizing area, the low-temperature deoxidizing area and the furnace end in sequence. A production method comprises the following steps of: burdening and mixing; loading into a boat, and conveying the boat; deoxidizing at a low temperature; carbonizing at a high temperature; and discharging to obtain the coarse-grained carbide powder. The carbon content of the produced carbide powder can be consistent with a certain requirement, and shortening of the service lives of furnace tubes, heating bodies, heat-preserving bodies and the like in the furnace caused by the losses of carbon/graphite materials can be prevented.