Carbide slag is used as raw material to produce cement. Because the content of harmful components of chloride ions and sulfur-alkali ratio of calcium carbide slag are much higher than those of limestone cement production line, the crusting of preheater and precalciner system has always been a major technological problem affecting the stable operation of rotary kiln. By adopting the sulfuric acid cleaning process instead of the hydrochloric acid cleaning process, the chloride ion content and the sulfur-alkali ratio in the raw materials are reduced; by controlling the combustion of pulverized coal, the local high temperature of the precalciner is avoided. After such measures, the skinning of the system has been reduced by more than 60%, realizing the efficient and stable operation of the system.