The invention discloses a low-temperature chlorination furnace shutdown heat-preservation method including the steps: carbonized slag and nitrogen gas are placed into a low-temperature chlorination furnace and undergo a reaction, and oxygen is contained in the nitrogen gas; nitrogen gas is added into the low-temperature chlorination furnace, and/or carbonated slag is added into the low-temperaturechlorination furnace. During normal production, the carbonized slag and chlorine gas undergo a reaction in the low-temperature chlorination furnace to produce titanium tetrachloride; and during shutdown heat preservation, the oxygen in the introduced nitrogen gas and a small amount of carbon in the carbonized slag undergo a reaction to produce heat to maintain the temperature of the materials at500 DEG C or more. Therefore, on the basis of raw materials, according to the low-temperature chlorination furnace shutdown heat-preservation method, the nitrogen gas is added into the low-temperaturechlorination furnace or the carbonized slag is added separately, the addition amount is adjusted to adjust the temperature of the chlorination furnace in a required range, or the nitrogen gas and thecarbonized slag are added at the same time, and the temperature of the low-temperature chlorination furnace can be effectively controlled; no new materials are needed to add, and the cost of production can be greatly reduced.