The cause of high power consumption in a cement plant and the effect of titanium slag on cement strength and strength growth rate were studied when titanium slag was used as cement mixture. The results show that TiO₂ content in titanium slag of cement factory is up to 12.76%, which leads to low activity of titanium slag. Poor grindability of titanium slag is the main reason of high power consumption in cement plant. Under the condition of the same specific surface area, titanium slag has little influence on the early strength of cement, but has obvious influence on the late strength. Under different specific surface area conditions, with the increase of specific surface area, the activity of both ordinary slag and titanium slag increases, while the activity of ordinary slag increases more obviously at 28d, and the activity of titanium slag at 28d increases to a certain extent, but not significantly.