The invention relates to a reduction chamber of an external heat type coal-based direct reduction iron shaft furnace. The reduction chamber is divided into a preheating section, a reducing section anda cooling section from top to bottom; the preheating section is provided with a converging air passage communicating with a rising pipe of a furnace top; sealing feed ports are formed in the top of the reduction chamber body; sealing discharge ports are formed in the bottom of the reduction chamber body; a cavity of the reduction chamber body is uniformly divided into n+1 holes by n reduction chamber partition walls in the length direction; 2-4 converging air channels are formed in the positions, at the two ends and/or inside the reduction chamber body, of each hole and correspond to the reduction chamber body in a communicating mode through a plurality of air leading-out holes arranged in the height direction; the tops of all the converging air channel communicate with the converging airpassage; and the bottoms of all the converging air channel communicate with the reduction chamber body. The reduction chamber has the advantages that the air permeability is good, the requirement forthe granularity of feed coal is not limited, the heat transfer condition is good, the structural strength is high, the single-hole capacity is high, and the phenomena that burden descent is not uniform and materials are stuck in the production process of sponge iron can be effectively avoided.