The invention discloses a tailing preheating device of a reduction kiln. The tailing preheating device comprises a preheating chamber (1), a smoke collection chamber (2) and a smoke extractor (3). The preheating chamber (1) is arranged on an outlet side of a preheating segment of a chain grate (4); space for containing kiln tailing is arranged inside the preheating chamber (1), a smoke inlet is formed in the front side of the preheating chamber (1), a smoke outlet is formed in the rear side of the preheating chamber (1), and the discharging end at the bottom of the preheating chamber (1) is located above a grid plate of the chain grate (4) and provided with a kiln tailing discharging device; the smoke collection chamber (2) is located on the rear side of the preheating chamber (1) and is communicated with the preheating chamber (1) through the smoke outlet; the smoke extractor (3) is arranged outside the smoke collection chamber (2) and used for extracting smoke in the smoke collection chamber (2). According to the preheating device, the kiln tailing preheating chamber is arranged on the preheating segment of the chain grate, and part of high-temperature smoke discharged by the tail of a reduction kiln is utilized for heating the kiln tailing; a heating device does not need to be additionally arranged, and energy can be effectively saved; running cost is reduced, and the device is compact in structure and reasonable in layout; and a utilization coefficient of kiln capacity is improved.